truck not running off alternator
#31
02-21-2012, 03:48 PM
I didn't post on here to debate whether or not to take the battery cable off a vehicle running is good or bad. Taking off didnt cause my problem,and leaving it on hasn't cured my problem,so that subject to me is niether here nor there. I posted on here to see if any one might know why my alternator bench tests good,but on my truck,not so much. I have physically checked all the fuses i could find and they are all good. like i said earlier,i havent had time yet to go around with my tester checking everything. The plug took 5min. to install and cost 10 bucks. Figured with my alotted time that would be a good place to start and what could it hurt
No offense but with reply #26 we didn't go too far.
#32
02-21-2012, 04:37 PM
This is not that difficult of a diagnosis. The debate, vague answers and somewhat incomplete information isn't helping any.
Attached is a wiring diagram for the alternator on your truck.
The A wire (Orange/Light Blue) is what the voltage regulator uses to determine the current voltage, so it knows how much to field the alternator. It is also what powers the field coils.
The I wire (Light Green/Red) is what turns the VR on and also what allows for the battery light to come on if necessary.
The stator circuit backfeeds power through the I wire, turning off the light if everything is OK. It isn't terribly relevant to this diagnoses.
According to the service manual, the I wire should have 1-3V on it with the key on, the A wire should have 12V at all times. (I'm assuming this is with the plug attached and probed through the back.) The A and I wires should have 12-15 volts with the engine running. If you have the correct voltage on the A and I wires with the key on, and the alternator is still not charging, the alternator is bad. Assuming also that you've checked all the terminals and grounds for corrosion and repaired as necessary.
It's about that simple.
Attached is a wiring diagram for the alternator on your truck.
The A wire (Orange/Light Blue) is what the voltage regulator uses to determine the current voltage, so it knows how much to field the alternator. It is also what powers the field coils.
The I wire (Light Green/Red) is what turns the VR on and also what allows for the battery light to come on if necessary.
The stator circuit backfeeds power through the I wire, turning off the light if everything is OK. It isn't terribly relevant to this diagnoses.
According to the service manual, the I wire should have 1-3V on it with the key on, the A wire should have 12V at all times. (I'm assuming this is with the plug attached and probed through the back.) The A and I wires should have 12-15 volts with the engine running. If you have the correct voltage on the A and I wires with the key on, and the alternator is still not charging, the alternator is bad. Assuming also that you've checked all the terminals and grounds for corrosion and repaired as necessary.
It's about that simple.
#33
02-21-2012, 05:00 PM
This is not that difficult of a diagnosis. The debate, vague answers and somewhat incomplete information isn't helping any.
Attached is a wiring diagram for the alternator on your truck.
The A wire (Orange/Light Blue) is what the voltage regulator uses to determine the current voltage, so it knows how much to field the alternator. It is also what powers the field coils.
The I wire (Light Green/Red) is what turns the VR on and also what allows for the battery light to come on if necessary.
The stator circuit backfeeds power through the I wire, turning off the light if everything is OK. It isn't terribly relevant to this diagnoses.
According to the service manual, the I wire should have 1-3V on it with the key on, the A wire should have 12V at all times. (I'm assuming this is with the plug attached and probed through the back.) The A and I wires should have 12-15 volts with the engine running. If you have the correct voltage on the A and I wires with the key on, and the alternator is still not charging, the alternator is bad. Assuming also that you've checked all the terminals and grounds for corrosion and repaired as necessary.
It's about that simple.
Attached is a wiring diagram for the alternator on your truck.
The A wire (Orange/Light Blue) is what the voltage regulator uses to determine the current voltage, so it knows how much to field the alternator. It is also what powers the field coils.
The I wire (Light Green/Red) is what turns the VR on and also what allows for the battery light to come on if necessary.
The stator circuit backfeeds power through the I wire, turning off the light if everything is OK. It isn't terribly relevant to this diagnoses.
According to the service manual, the I wire should have 1-3V on it with the key on, the A wire should have 12V at all times. (I'm assuming this is with the plug attached and probed through the back.) The A and I wires should have 12-15 volts with the engine running. If you have the correct voltage on the A and I wires with the key on, and the alternator is still not charging, the alternator is bad. Assuming also that you've checked all the terminals and grounds for corrosion and repaired as necessary.
It's about that simple.
#34
02-21-2012, 05:10 PM
I wasn't giving YOU anything. I was commenting on the general tone of the entire thread.
I watched the thread for awhile, and I didn't get involved because I don't have a 99, nor a V-10. So the only help I could provide was from the service manuals, and they aren't always 100% accurate.
I finally responded because it didn't look like the guy was really getting much help. Your last post was good. I couldn't follow it, because I don't have the truck to look at. But it was still a good post.
I really think you need to relax. Life is too short to get pissed off over the stupid internet.
I watched the thread for awhile, and I didn't get involved because I don't have a 99, nor a V-10. So the only help I could provide was from the service manuals, and they aren't always 100% accurate.
I finally responded because it didn't look like the guy was really getting much help. Your last post was good. I couldn't follow it, because I don't have the truck to look at. But it was still a good post.
I really think you need to relax. Life is too short to get pissed off over the stupid internet.
#35
02-21-2012, 08:38 PM
#36
02-21-2012, 11:23 PM
So Is it fixed? The single wire to the alt if unplugged will turn the light on those connectors corrode bad..I would get another alt or have it checked again.
Power 12v at A and B+ all the time. wires disconnected
Power at I when key on wires disconnected...How it works is key on 12v to one side of bulb reg grounds other side with engine off so light on. engine on.. ground comes off bulb it goes out.
The jumper has to be shorting S to S
If the light is on you know I is hooked up ok.
Because the light is on S to S might be not making connection.
Dick
Power 12v at A and B+ all the time. wires disconnected
Power at I when key on wires disconnected...How it works is key on 12v to one side of bulb reg grounds other side with engine off so light on. engine on.. ground comes off bulb it goes out.
The jumper has to be shorting S to S
If the light is on you know I is hooked up ok.
Because the light is on S to S might be not making connection.
Dick
#37
02-22-2012, 03:13 AM
yeah,I took 5 seconds to check the plug. Just because theres power @ the plug doesnt mean the plug is making good contact on the alternator
#38
02-22-2012, 05:17 AM
#39
02-22-2012, 05:28 AM
I've got power everywhere except out of the alternator. Changed alternator out last night and still nothing. Unfortunately I'm to the point that I'm gonna take to the shop. I just don't have the time or patience to mess with it anymore.
#40
02-22-2012, 05:40 AM
#41
02-22-2012, 05:48 AM
Yeah,when it gets figured out I'll let everyone know. I hope my local shop can figure it out too!! Either way they hopefully have more electrical knowledge than I do
#42
02-22-2012, 08:38 AM
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Maybe I missed it, but how old is your battery and have you actually tested it? I bought my truck in '04 new in '07 my I was plowing snow and truck started dying, my first thought was alt. , but it turned out I had a bad (factory)battery, it would be fine and then it wouldn't, haven't had a problem since.....knock on wood
#43
02-22-2012, 09:00 AM
Maybe I missed it, but how old is your battery and have you actually tested it? I bought my truck in '04 new in '07 my I was plowing snow and truck started dying, my first thought was alt. , but it turned out I had a bad (factory)battery, it would be fine and then it wouldn't, haven't had a problem since.....knock on wood
#44
02-22-2012, 09:10 AM
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#45
02-23-2012, 04:41 PM
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