trailer brakes not working
#16
09-09-2013, 11:34 AM
Resurrecting this thread to see if the problem was ever solved. My 2011 F250 started having the exact same problem - no trailer brakes using the pedal, but manual control worked fine. Truck brake lights function normally, so I suppose the brake switch is good. As I recall, doesn't the trailer gain screen show when the trailer is connected and the brake pedal is depressed under normal braking conditions? If that is correct, it now does not appear using the brake pedal, but does when using the manual controller.
The trailer is not the problem. Trailer brakes function normally when connected to my 2000 F550. (Aftermarket controller.) They are setup correctly and the break-away switch locks them up!
The trailer is not the problem. Trailer brakes function normally when connected to my 2000 F550. (Aftermarket controller.) They are setup correctly and the break-away switch locks them up!
#17
09-09-2013, 06:21 PM
Resurrecting this thread to see if the problem was ever solved. My 2011 F250 started having the exact same problem - no trailer brakes using the pedal, but manual control worked fine. Truck brake lights function normally, so I suppose the brake switch is good. As I recall, doesn't the trailer gain screen show when the trailer is connected and the brake pedal is depressed under normal braking conditions? If that is correct, it now does not appear using the brake pedal, but does when using the manual controller.
The trailer is not the problem. Trailer brakes function normally when connected to my 2000 F550. (Aftermarket controller.) They are setup correctly and the break-away switch locks them up!
The trailer is not the problem. Trailer brakes function normally when connected to my 2000 F550. (Aftermarket controller.) They are setup correctly and the break-away switch locks them up!
Steve
Steve
#18
09-09-2013, 08:20 PM
Thanks for the reply Steve. It must be a failed IBC, because I'm towing an 9000 load (trailer and backhoe) up and down PA hills and I'm certainly not feathering the brakes.
It goes to the dealer for warranty repair on Wed. I just hope they have a tech as smart as you and all the other experts on this site, because nothing angers me more when a shop with "factory trained technicians" can't fix something but insults my intelligence by giving me a lame a$$ excuse for not being able to fix it. ....not to mention my time and gas wasted for return trips.
They are making me bring my trailer with the truck, which tells me they are trying to pass the blame to the trailer even though I've told them about it working fine with another vehicle. Grrrrrr, I'm starting to get a bit warm now just thinking about it!
BTW, am I correct about the trailer gain screen showing when the brake pedal is depressed and the IBC is activated?
It goes to the dealer for warranty repair on Wed. I just hope they have a tech as smart as you and all the other experts on this site, because nothing angers me more when a shop with "factory trained technicians" can't fix something but insults my intelligence by giving me a lame a$$ excuse for not being able to fix it. ....not to mention my time and gas wasted for return trips.
They are making me bring my trailer with the truck, which tells me they are trying to pass the blame to the trailer even though I've told them about it working fine with another vehicle. Grrrrrr, I'm starting to get a bit warm now just thinking about it!
BTW, am I correct about the trailer gain screen showing when the brake pedal is depressed and the IBC is activated?
#19
09-09-2013, 08:39 PM
Thanks for the reply Steve. It must be a failed IBC, because I'm towing an 9000 load (trailer and backhoe) up and down PA hills and I'm certainly not feathering the brakes.
It goes to the dealer for warranty repair on Wed. I just hope they have a tech as smart as you and all the other experts on this site, because nothing angers me more when a shop with "factory trained technicians" can't fix something but insults my intelligence by giving me a lame a$$ excuse for not being able to fix it. ....not to mention my time and gas wasted for return trips.
They are making me bring my trailer with the truck, which tells me they are trying to pass the blame to the trailer even though I've told them about it working fine with another vehicle. Grrrrrr, I'm starting to get a bit warm now just thinking about it!
BTW, am I correct about the trailer gain screen showing when the brake pedal is depressed and the IBC is activated?
It goes to the dealer for warranty repair on Wed. I just hope they have a tech as smart as you and all the other experts on this site, because nothing angers me more when a shop with "factory trained technicians" can't fix something but insults my intelligence by giving me a lame a$$ excuse for not being able to fix it. ....not to mention my time and gas wasted for return trips.
They are making me bring my trailer with the truck, which tells me they are trying to pass the blame to the trailer even though I've told them about it working fine with another vehicle. Grrrrrr, I'm starting to get a bit warm now just thinking about it!
BTW, am I correct about the trailer gain screen showing when the brake pedal is depressed and the IBC is activated?
They should be able to troubleshoot this in about five minutes. You plug in the tester and activate the brakes on manual. If it shows enough amps, the wiring is good, the controller is bad, provided it doesn't do the same thing when stopping as you do with it on manual.
If it was the trailer connection, you should see a trailer disconnect warning on your screen and should be getting that message when you are traveling.
Now, if I plugged my tester into your seven pin and we took a ride and it showed good on my tester, the issue would be your trailer and I would not have to have your trailer to tell you that. But, if it was your trailer, it would only take about five minutes more to tell you where the problem was there. Maybe they intend to actually troubleshoot, glory be!
I know everyone want to act like the TBC is the second coming, but all it does it combine two very old technologies (and seems to confuse the crap out of folks at the same time).
Steve
#20
09-20-2013, 10:22 AM
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Once again...time to res-erect this thread!
2009 Ford F450, and I have a similar problem. Unfortunately, I have already taken my truck to the local Ford dealer, and was charged for them finding 'nothing'. Understandably, it was for their time.
Now...with that said, I've had to do all the searching myself, as I too have functioning trailer brakes when using the slide controller, but get nothing with the brake pedal. Taking the truck for a drive, with the controller set on high, using the brake pedal I get a no brake issue.
I initially thought it was the 'blue' wire, which I've found out is the wire for the trailer brakes. Upon further review, and buying a $30.00 tester, I find my blue wire is working fine (jacked up the trailer, and spun the wheel) and the brakes work fine 'with the controller'.
So, in my instructions, when I plug in my tester, it states, that the 12V LED light should illuminate as soon as the tester is inserted...so I now find that this is the problem (I think) as I'm getting nothing from the 12V connection within the 7 pin connector at the back of the truck. Yes, all others seem to work, signals, brake lights etc. on both truck & trailer when plugged in.
It states that with the 12V not illuminating, "12V light on the emulator will be lit as soon as the emulator is connected to the tow vehicle's plug". If this does no happen see troubleshooting chart".
Doing that...I get "Bad ground or poor connection in the circuit".
With that said, I'm back to square one, not knowing where to check?
I 'did' check at the controller, and there is definitely power coming out of the controller for the 'blue' wire, and originally I thought there has to be power to the red wire, (12V at the controller) or there would be no power coming from the controller itself?
This has been an ongoing issue now for over a week, and I still have no brakes with the pedal...only manually using the controller.
Frustration is the word of the day, as while doing all this testing, I go around the passenger side of my truck (dually) and I see one of my rear fender lights...hanging out from it's location! Truck (to me) is still a pretty new truck and I'm **** at keeping it clean and tidy...and it's giving me all this grief! Oh...and I'm needing the trailer for a vacation next weekend on top of all this.
Thought I should add, when the trailer is connected, it shows this on my instrument panel screen, so whatever shows this, that portion is working as well.
As a test, if I drive down the road with my trailer connected to the truck, and I raise the gain up to say...8...should the brakes lock up on the trailer? (trailer is empty..and is a 18' enclosed dual axle).
Thanks in advance for any info/advice/help on this matter. If any other info is needed, please just ask.
PSD2000
2009 Ford F450, and I have a similar problem. Unfortunately, I have already taken my truck to the local Ford dealer, and was charged for them finding 'nothing'. Understandably, it was for their time.
Now...with that said, I've had to do all the searching myself, as I too have functioning trailer brakes when using the slide controller, but get nothing with the brake pedal. Taking the truck for a drive, with the controller set on high, using the brake pedal I get a no brake issue.
I initially thought it was the 'blue' wire, which I've found out is the wire for the trailer brakes. Upon further review, and buying a $30.00 tester, I find my blue wire is working fine (jacked up the trailer, and spun the wheel) and the brakes work fine 'with the controller'.
So, in my instructions, when I plug in my tester, it states, that the 12V LED light should illuminate as soon as the tester is inserted...so I now find that this is the problem (I think) as I'm getting nothing from the 12V connection within the 7 pin connector at the back of the truck. Yes, all others seem to work, signals, brake lights etc. on both truck & trailer when plugged in.
It states that with the 12V not illuminating, "12V light on the emulator will be lit as soon as the emulator is connected to the tow vehicle's plug". If this does no happen see troubleshooting chart".
Doing that...I get "Bad ground or poor connection in the circuit".
With that said, I'm back to square one, not knowing where to check?
I 'did' check at the controller, and there is definitely power coming out of the controller for the 'blue' wire, and originally I thought there has to be power to the red wire, (12V at the controller) or there would be no power coming from the controller itself?
This has been an ongoing issue now for over a week, and I still have no brakes with the pedal...only manually using the controller.
Frustration is the word of the day, as while doing all this testing, I go around the passenger side of my truck (dually) and I see one of my rear fender lights...hanging out from it's location! Truck (to me) is still a pretty new truck and I'm **** at keeping it clean and tidy...and it's giving me all this grief! Oh...and I'm needing the trailer for a vacation next weekend on top of all this.
Thought I should add, when the trailer is connected, it shows this on my instrument panel screen, so whatever shows this, that portion is working as well.
As a test, if I drive down the road with my trailer connected to the truck, and I raise the gain up to say...8...should the brakes lock up on the trailer? (trailer is empty..and is a 18' enclosed dual axle).
Thanks in advance for any info/advice/help on this matter. If any other info is needed, please just ask.
PSD2000
#21
09-20-2013, 08:00 PM
Once again...time to res-erect this thread!
2009 Ford F450, and I have a similar problem. Unfortunately, I have already taken my truck to the local Ford dealer, and was charged for them finding 'nothing'. Understandably, it was for their time.
Did they offer any feedback?
Now...with that said, I've had to do all the searching myself, as I too have functioning trailer brakes when using the slide controller, but get nothing with the brake pedal. Taking the truck for a drive, with the controller set on high, using the brake pedal I get a no brake issue.
So you can lock em up with the manual slide, but nothing at all happens with the pedal?
I initially thought it was the 'blue' wire, which I've found out is the wire for the trailer brakes. Upon further review, and buying a $30.00 tester, I find my blue wire is working fine (jacked up the trailer, and spun the wheel) and the brakes work fine 'with the controller'.
I presume with the manual slide in which case you already knew this without jacking up the trailer.
So, in my instructions, when I plug in my tester, it states, that the 12V LED light should illuminate as soon as the tester is inserted...so I now find that this is the problem (I think) as I'm getting nothing from the 12V connection within the 7 pin connector at the back of the truck. Yes, all others seem to work, signals, brake lights etc. on both truck & trailer when plugged in.
It states that with the 12V not illuminating, "12V light on the emulator will be lit as soon as the emulator is connected to the tow vehicle's plug". If this does no happen see troubleshooting chart".
With the ignition on. If no light, possible fuse issue in box under hood.
Doing that...I get "Bad ground or poor connection in the circuit".
Or no power to the circuit.
With that said, I'm back to square one, not knowing where to check?
I 'did' check at the controller, and there is definitely power coming out of the controller for the 'blue' wire, and originally I thought there has to be power to the red wire, (12V at the controller) or there would be no power coming from the controller itself?
Again you know there is power from the controller as you can activate the trailer brakes using the slide.
This has been an ongoing issue now for over a week, and I still have no brakes with the pedal...only manually using the controller.
Frustration is the word of the day, as while doing all this testing, I go around the passenger side of my truck (dually) and I see one of my rear fender lights...hanging out from it's location! Truck (to me) is still a pretty new truck and I'm **** at keeping it clean and tidy...and it's giving me all this grief! Oh...and I'm needing the trailer for a vacation next weekend on top of all this.
Thought I should add, when the trailer is connected, it shows this on my instrument panel screen, so whatever shows this, that portion is working as well.
So the controller is finding your trailer. That means the connection is intact and the magnets are on board as it is reading the resistance of the circuit.
As a test, if I drive down the road with my trailer connected to the truck, and I raise the gain up to say...8...should the brakes lock up on the trailer? (trailer is empty..and is a 18' enclosed dual axle).
It is hard for me to answer this with having data from an amp meter so I know how much current is actually flowing to you trailer brakes, but you certainly should feel it. Again are you doing this with the manual slide?
Thanks in advance for any info/advice/help on this matter. If any other info is needed, please just ask.
PSD2000
2009 Ford F450, and I have a similar problem. Unfortunately, I have already taken my truck to the local Ford dealer, and was charged for them finding 'nothing'. Understandably, it was for their time.
Did they offer any feedback?
Now...with that said, I've had to do all the searching myself, as I too have functioning trailer brakes when using the slide controller, but get nothing with the brake pedal. Taking the truck for a drive, with the controller set on high, using the brake pedal I get a no brake issue.
So you can lock em up with the manual slide, but nothing at all happens with the pedal?
I initially thought it was the 'blue' wire, which I've found out is the wire for the trailer brakes. Upon further review, and buying a $30.00 tester, I find my blue wire is working fine (jacked up the trailer, and spun the wheel) and the brakes work fine 'with the controller'.
I presume with the manual slide in which case you already knew this without jacking up the trailer.
So, in my instructions, when I plug in my tester, it states, that the 12V LED light should illuminate as soon as the tester is inserted...so I now find that this is the problem (I think) as I'm getting nothing from the 12V connection within the 7 pin connector at the back of the truck. Yes, all others seem to work, signals, brake lights etc. on both truck & trailer when plugged in.
It states that with the 12V not illuminating, "12V light on the emulator will be lit as soon as the emulator is connected to the tow vehicle's plug". If this does no happen see troubleshooting chart".
With the ignition on. If no light, possible fuse issue in box under hood.
Doing that...I get "Bad ground or poor connection in the circuit".
Or no power to the circuit.
With that said, I'm back to square one, not knowing where to check?
I 'did' check at the controller, and there is definitely power coming out of the controller for the 'blue' wire, and originally I thought there has to be power to the red wire, (12V at the controller) or there would be no power coming from the controller itself?
Again you know there is power from the controller as you can activate the trailer brakes using the slide.
This has been an ongoing issue now for over a week, and I still have no brakes with the pedal...only manually using the controller.
Frustration is the word of the day, as while doing all this testing, I go around the passenger side of my truck (dually) and I see one of my rear fender lights...hanging out from it's location! Truck (to me) is still a pretty new truck and I'm **** at keeping it clean and tidy...and it's giving me all this grief! Oh...and I'm needing the trailer for a vacation next weekend on top of all this.
Thought I should add, when the trailer is connected, it shows this on my instrument panel screen, so whatever shows this, that portion is working as well.
So the controller is finding your trailer. That means the connection is intact and the magnets are on board as it is reading the resistance of the circuit.
As a test, if I drive down the road with my trailer connected to the truck, and I raise the gain up to say...8...should the brakes lock up on the trailer? (trailer is empty..and is a 18' enclosed dual axle).
It is hard for me to answer this with having data from an amp meter so I know how much current is actually flowing to you trailer brakes, but you certainly should feel it. Again are you doing this with the manual slide?
Thanks in advance for any info/advice/help on this matter. If any other info is needed, please just ask.
PSD2000
You can activate the trailer brakes and I assume really feel the trailer brakes with the power dialed up using the manual slide. That means the trailer brakes are good, the seven pin connection is good, and the truck wiring is good. That leaves nothing except the controller unless I am really missing something here.
The only thing that changes when you use the pedal is the brakes are activated via a different mechanism.
The fact that your charge pin is dead on the seven pin has nothing to do with the trailer brakes. A bad ground would, but that would also affect everything else on the trailer i.e. lights, brakes using manual slide, etc. and you said those are all working fine, i.e. the ground is good.
If you want to test for a bad grounding issue just take a jumper cable and attach one jaw to a spot on the trailer where it can make good connection to the frame and do the same to the frame of the truck. Now you have established a good ground.
Steve
#23
10-12-2014, 05:12 PM
I have this same issue......
on my 2012 F250 Super Duty.......I have excellent trailer braking when I manually apply the trailer brakes with the OEM TBC's slider on the dash.....I have nothing when I press the brake pedal even with the gain set at 10.
I've been to the dealer three times now and spent the majority of the day sitting there while they work on it..... They performed a "Pin-test" which indicated the TBC on the dash had failed so they replaced it....Took it out for a ride with the tech and my trailer attached and before we had even gotten off the dealership property I could tell nothing had changed..... I showed the tech it works with manual activation but nothing when depressing the brake pedal....
I am scheduled to go back to the dealership (Gary Yeomans Ford) at 7am tomorrow to sit there again not knowing if they will find and fix the problem again..... I am about over this already..... I've only had the truck 6 weeks and have had to return to the dealer 6 times now (100 miles from my home) so I am a bit annoyed.....
If anybody figures out what it takes to fix it PLEASE let me know.
Thanks
I've been to the dealer three times now and spent the majority of the day sitting there while they work on it..... They performed a "Pin-test" which indicated the TBC on the dash had failed so they replaced it....Took it out for a ride with the tech and my trailer attached and before we had even gotten off the dealership property I could tell nothing had changed..... I showed the tech it works with manual activation but nothing when depressing the brake pedal....
I am scheduled to go back to the dealership (Gary Yeomans Ford) at 7am tomorrow to sit there again not knowing if they will find and fix the problem again..... I am about over this already..... I've only had the truck 6 weeks and have had to return to the dealer 6 times now (100 miles from my home) so I am a bit annoyed.....
If anybody figures out what it takes to fix it PLEASE let me know.
Thanks
#24
10-13-2014, 09:35 AM
Did you do a voltage test/pin out of the electrical hookup (7pin connector) below the rear bumper ? When someone pushes the brake pedal you should have 3-5 volts at the BLUE wire. Once you get to 5-15 MPH it will go to 12v.
Here are the standard wiring color sequence:
Yellow = Left turn
Green = Right turn
Brown = Tail/Marker
Blue = Trailer Brakes
Black = +12 volt source (ie breakaway battery charge)
Orange = Backup/Auxiliary
White = Ground
Here are the standard wiring color sequence:
Yellow = Left turn
Green = Right turn
Brown = Tail/Marker
Blue = Trailer Brakes
Black = +12 volt source (ie breakaway battery charge)
Orange = Backup/Auxiliary
White = Ground
#25
10-13-2014, 02:36 PM
#27
10-13-2014, 04:56 PM
On my first trip to the dealer i had less then a volt on the blue trailer brake wire under all braking at any speed. Not even enough to activate the magnets on the trailer. They did a pin test and determined the TBC was bad and replaced it. It didn't fix it but we now had 3.4 to 3.8 volts on the blue trailer output wire at any braking speed. On the second trip he spent several hours and did not come up with anything new. He contacted the Ford hotline and they had him check the 7 way for corrosion. Again it still wasn't fixed. Low output voltage from the TBC. Today, my third trip to the dealer, he said hotline had him check a chassis ground mid truck and to replace the 7way on the back of the truck. Tech said the ground was loose, he tightened it and now we're getting 5.8-6.5 volts under 45 mph and 10.3 to 13.8 over 45 mph.
The trailer brakes are now working but to me they still don't grab like they did behind my F150. With the trailer gain set at 6 or 7 and my car hauler empty the tires would lock up... Behind the Super Duty, same trailer empty they barely lock up with gain at 9...
I think there is still a problem but the dealer says its now working and isn't going to do anymore. I think there should be higher output voltages at slower speeds personally. I'm gonna have stopping problems when I put another mini excavator on my trailer if the trailer brakes don't do more then they are now.
My F150 would stop on a dime with the excavator on the back and it was severely over weight with it on there hence the purchase of the F250.
#28
10-13-2014, 05:11 PM
#29
10-13-2014, 05:37 PM
There is a transducer in the circuit that converts pedal pressure to supply voltage. First let's slow down for a minute and make sure we still have a problem. I can't tell you where it is located as I stop diagnosing when I determine something is amiss with the TBC and send the customer to Ford.
Even under hard braking you should not feel the trailer brakes engage when everything is set correctly as the trailer brakes activating in line with amount of pedal pressure and the rate at which your truck is deaccelerating. Trailer braking is completely seamless. Let's suppose you are moving at 60 mph and stomp the brakes, Your trailer brakes should activate to the same degree. If you are seeing 13.8 at the pin, you are not going to see anymore than that. The power to the brakes is maxed out.
Here is the part I don't understand. Why did the tech not start by checking the things he did today on the first run through? Those are the basics that everyone should cover before doing anything else. I am also not clear how the brakes worked so well on the manual override, but so poorly with the pedal if it is a grounding issue.
Now for the next step you need to know how many amps the trailer brakes are drawing. You need an amp meter on the blue lead at the trailer and then just activate the brakes with a battery and take a reading. You should see over 10 amps. If you do and you still don't have brakes the shoes need adjusting or there is a mechanical issue with the brakes. If you don't see it, there is an electrical issue with the trailer brakes.
That's about as far as I can take you. I will tell you that the TBC is not a frequent problem. although I would opine it is poorly understood and lacks the onboard diagnostics found in many high-end after-market controllers.
Steve
Even under hard braking you should not feel the trailer brakes engage when everything is set correctly as the trailer brakes activating in line with amount of pedal pressure and the rate at which your truck is deaccelerating. Trailer braking is completely seamless. Let's suppose you are moving at 60 mph and stomp the brakes, Your trailer brakes should activate to the same degree. If you are seeing 13.8 at the pin, you are not going to see anymore than that. The power to the brakes is maxed out.
Here is the part I don't understand. Why did the tech not start by checking the things he did today on the first run through? Those are the basics that everyone should cover before doing anything else. I am also not clear how the brakes worked so well on the manual override, but so poorly with the pedal if it is a grounding issue.
Now for the next step you need to know how many amps the trailer brakes are drawing. You need an amp meter on the blue lead at the trailer and then just activate the brakes with a battery and take a reading. You should see over 10 amps. If you do and you still don't have brakes the shoes need adjusting or there is a mechanical issue with the brakes. If you don't see it, there is an electrical issue with the trailer brakes.
That's about as far as I can take you. I will tell you that the TBC is not a frequent problem. although I would opine it is poorly understood and lacks the onboard diagnostics found in many high-end after-market controllers.
Steve
#30
10-13-2014, 06:43 PM
There is a transducer in the circuit that converts pedal pressure to supply voltage. First let's slow down for a minute and make sure we still have a problem. I can't tell you where it is located as I stop diagnosing when I determine something is amiss with the TBC and send the customer to Ford.<br />
<br />
Even under hard braking you should not feel the trailer brakes engage when everything is set correctly as the trailer brakes activating in line with amount of pedal pressure and the rate at which your truck is deaccelerating. Trailer braking is completely seamless. Let's suppose you are moving at 60 mph and stomp the brakes, Your trailer brakes should activate to the same degree. If you are seeing 13.8 at the pin, you are not going to see anymore than that. The power to the brakes is maxed out.<br />
<br />
Here is the part I don't understand. Why did the tech not start by checking the things he did today on the first run through? Those are the basics that everyone should cover before doing anything else. I am also not clear how the brakes worked so well on the manual override, but so poorly with the pedal if it is a grounding issue.<br />
<br />
Now for the next step you need to know how many amps the trailer brakes are drawing. You need an amp meter on the blue lead at the trailer and then just activate the brakes with a battery and take a reading. You should see over 10 amps. If you do and you still don't have brakes the shoes need adjusting or there is a mechanical issue with the brakes. If you don't see it, there is an electrical issue with the trailer brakes.<br />
<br />
That's about as far as I can take you. I will tell you that the TBC is not a frequent problem. although I would opine it is poorly understood and lacks the onboard diagnostics found in many high-end after-market controllers. <img src="http://images.ford-trucks.com/forums/images/smilies/happy0161.gif" border="0" alt="" title="Smilie" smilieid="1" class="inlineimg" /><br />
<br />
Steve
<br />
Even under hard braking you should not feel the trailer brakes engage when everything is set correctly as the trailer brakes activating in line with amount of pedal pressure and the rate at which your truck is deaccelerating. Trailer braking is completely seamless. Let's suppose you are moving at 60 mph and stomp the brakes, Your trailer brakes should activate to the same degree. If you are seeing 13.8 at the pin, you are not going to see anymore than that. The power to the brakes is maxed out.<br />
<br />
Here is the part I don't understand. Why did the tech not start by checking the things he did today on the first run through? Those are the basics that everyone should cover before doing anything else. I am also not clear how the brakes worked so well on the manual override, but so poorly with the pedal if it is a grounding issue.<br />
<br />
Now for the next step you need to know how many amps the trailer brakes are drawing. You need an amp meter on the blue lead at the trailer and then just activate the brakes with a battery and take a reading. You should see over 10 amps. If you do and you still don't have brakes the shoes need adjusting or there is a mechanical issue with the brakes. If you don't see it, there is an electrical issue with the trailer brakes.<br />
<br />
That's about as far as I can take you. I will tell you that the TBC is not a frequent problem. although I would opine it is poorly understood and lacks the onboard diagnostics found in many high-end after-market controllers. <img src="http://images.ford-trucks.com/forums/images/smilies/happy0161.gif" border="0" alt="" title="Smilie" smilieid="1" class="inlineimg" /><br />
<br />
Steve
<br />
Thanks Steve for your assistance. <br />
<br />
Let me begin by saying I am only relaying what the service tech relayed to me. I do not know why he didn't check grounds more thoroughly on previous visits. I asked him on the second visit if there was a chance I had a bad ground in the TBC circuit and he said that the IBS did not indicate one. He did seem to be baffled by the whole situation and today had two other techs working on it with him<br />
On my first visit he relied on a TSB he found that matched my complaint which directed him to do the pin test. Pin test lead to a faulty TBC so he replaced it. Still had low output voltage at all braking speeds... (Under 4v) I was standing there today when he called the ford hotline and heard the entire conversation he had with them. He explained it would <br />
Work great manually but low voltage with the pedal. They told him to check this ground mid truck and for corrosion at the 7 way. No corrosion but tech said ground was poor.. <br />
<br />
I understand the system is designed to apply increasing voltage as brake pressure increases and it also uses an accelerometer to determine the decline in speed... What I don't understand is why the gain has little effect on the stopping power of the trailer... The gain made huge differences on my F150. I drove home from the dealer today (100+ miles) and played with the gain... Under 5 it felt like I had no trailer braking at all when I feel there should of been a little bit. At 10 the trailer would barely lock up the tires and only if I really stomped down on the brake pedal. My F150 would lock up the empty trailer with gain anything over 6 . <br />
<br />
I know I am comparing a 6000 lb truck to a 7900 lb truck but I would think the trailer braking shouldn't change in regards to what is felt at certain gain settings.
To add, I have 4 trailers, a 2006 big TeX car hauler that I just had the front axle brakes replaced and added brakes to the rear axle so all 4 wheels have brakes. A 2009 big TeX 39 foot deck over gooseneck with brakes on both axles. This trailer only has about 5000 miles on it. A Gator made 30ft bumper pull car hauler tri-axle with brakes on two axles and a 2012 38 ft Redwood Fifth wheel RV.
I plan on towing each trailer in the next week to see how it works with each one. I'm hoping I don't have to run all of them with the gain so high. <br />
<br />
Jess