Hello, I have a 97 F350 7.5L and I am trying to tow a trailer with it. I have attached pictures of the connector for the trailer and on the back of the truck. My auto parts stores have no idea what I need. Please let me know
if you have any clue. By the way, this truck is so rusted If the wiring on the truck is there I don't even know if it works. Is it hard or expensive to rewire it for the new connector? Also please tell me how the brakes work on my trailer? How does the trailer know when you brake based on how much pressure i put on the pedal? Is there a park on the hitch that senses how much brake is needed when I slow down? Thanks.

 

Your auto parts store MIGHT have an adapter from a 6 pin to a 7 pin. But even if they do, I'm not sure a 6 pin was ever much of a standard, so it might not work right anyway.

They should have a 6 pin plug and a 7 pin socket that you can use to make your own adapter. It's not that hard. I'd start bu hooking short pieces of wire to your new 6 pin plug. Make sure the ends don't touch each other! Then take a volt meeter and start trying to figure out what each wire is. Start off by hooking the black lead on your volt meter to a good ground on the truck, then turn on the tail linghts and touch the red lead on the volt meter to each wire until you find one with a little over 12 volts. Then turn off the tail lights and that wire should have 0 volts. you can do this to find the tail, left turn and right turn wires.

Once you have those you need to figure out the other 3. One will be ground, the others will be 2 of the following 3 things: backup lights, +12 volts or trailer brakes. You should be able to hook your volt meter black lead to the ground wire and get readings as you touch the red wire to all of the other wires (when they are turned on of course).

Once you have all of the wires on the truck figured out it's time to figure out the trailer. I don't have a super easy way to do that. Try to find the ground first. If you open up the trailer plug it'll probably have a white wire (or possibly black) going to it. It's also probably the biggest wire in the bunch. Hook up your ground and then turn on the rail lights and touch that wire to each of the trailer plug wires to see what comes on. Once you get everything figured out you can hook up the wires and you have your adapter.


It's a good idea to use standard wire colors so it's easier to figure things out later. On trailer wires:

• brown is tail lights
• yellow is left turn
• green is right turn
• white is (usually) ground
• red is +12 volts
• blue (I think) is trailer brakes
• black (I think) is backup lights

Your truck only has 6 pins and the trailer has 7, so something on the trailer won't be hooked up. It'll probably be the backup lights, trailer brakes or +12 volts. You'll have to decide if you can live without whatever is missing.

 

I would do away with that current plug you have now.

Just get a 7 RV plug(what your trailer is)
7-Way Plastic Connector - RV Blade - Vehicle End - By Curt Mfg

 

You also asked about rewiring your truck if the existing plug doesn't work. That's not that hard either, but it always takes me a lot longer than I think it should.

If you're going to go this way, get a 7 pin socket so it'll work with your trailer without an adapter.

Your ground wire should be pretty heavy. I like to use 10 gage wire. The best way to get a good ground is to drill a hole in your frame and either tap threads in it or use a self threading screw to go through an eye you've crimped (and soldered, if you want to make sure you don't have problems) to your ground wire. Sand or grind the frame clean so you get good contact, then it's not a bad idea to put something like antiseize over it after you connect it to keep it from rusting.

The easiest way to get turn and tail light wires is in the tail lights. Your auto store will have connectors that let you hook your trailer harness wires up to the existing wires without cutting the existing wires. You can get you backup lights wire the same way.

One caution with that, if your trailer has a lot of lights you might overload your truck circuit and blow a fuse. There are ways to avoid that, but I'm not going into them here. I've never had a problem doing it like i said above anyway.

The +12 volt and trailer brake wires are a little harder (if you need them). You can try to get them from your existing plug (if they work). Otherwise it's probably easiest to just run new wires from the front of the truck. Make sure you use a fuse on the +12 volts and you'll need a trailer brake controller to hook the trailer brake wire to.

Good luck

 

I agree with Brad here, just get a 7 pin and be done with it.. That six pin looks like it is past due for the scrap pile...

As far as what tells the brakes how much power to apply, that's what the brake controller is for.. You don't just hook 12 volts to the brakes.....

 

Do I even have a brake controller? I believe they are small devices that look like radar detectors. I don't have one in my truck. I'm still unsure how it knows how much brake to apply.

 

You might say it resembles a radar detector.. They are usually mounted under the steering column...

Here is some info on controllers, If I try to explain it we will both be confused!!!

Trailer Brake Controller Information | etrailer.com

 

Correct, they kind look like a radar detector and are typically mounted under the dash. What size trailer are you towing? Typically anything with the 7 rv plug has brakes and any trailer over 3,000lb gvw NEEDS brakes

Alot of trucks were equipped with the harness to PLUG in a brake controller. The harness is tucked up under the dash over the trans hump. It is a 6 pin rectangular plug. The pig tail to plug into it (some came from the factory) is in the glove box or most auto parts stores have them
Here is the one you need
Buy Reese Towing Brake Control Harness 78054 at Advance Auto Parts

Also under the hood in the power distrubution panel

You need a 30 amp fuse to power the trailer brakes(location 21)
you need a 10 amp fuse to power the left turn signal(location 7)
you need a 10 amp fuse to power the right turn signal(location 6)
you need a 15 amp fuse to power trailer batter brake away battery(location5)
you need a 10 amp fuse to power the left turn signal(location 7)

you need a RELAY to power theMarker lamps(location relay5)

 

There are three basic types of brake controller as far as I know. All of them give more voltage to the trailer brakes to give more braking force or less to give less.

The simplest / cheapest / most common has 4 wires: +12 volts, ground, a signal from your brake lights and a feed wire to your trailer brakes. Whenever your brake lights go on the controller starts steadily increasing (ramping up) the voltage to some maximun level. You can adjust what the maximum is, and you can adjust how fast it ramps up, but any time you hit the brake pedal it does the same thing, whether you are slamming on the brakes in a panic stop or touching them lightly to slow down for a stop. Since it does the same thing every time it almost never does what you want it to do. I would not suggest this type unless you don't do much towing at all, or unless your trailer is pretty small and you can almost get away without trailer brakes. If you do get this type, one way to make it work better is to set it to work best for the slow, gradual stops, and then use the manual actuation for panic stops. There will be a button or lever you can work by hand to make the brakes come on right now. This works well, but it does require you to take one hand off the wheel and use it to work the trailer brakes when you are already in a panic situation.

The next most common kind probably also has the same 4 wires, although it might not have the brake light wire. This kind has an accelerometer that senses how quickly the truck is slowing down and gives more trailer brake when you are slowing down faster. Again you will need to adjust the maximum braking level ahead of time, but now the brake controller can think for itself about how hard to slam on the trailer brakes. I've never used this type of controller myself, but it seems a lot safer than the first kind. The one risk I can imagine is that, especially with a big trailer behind a smaller truck, as the trailer brakes come on the truck will slow down and the brake controller might see that as a signal to hit the trailer brakes even harder. I could imagine this getting into a feedback loop where you don't have very good control over the brakes, but again, I've never used this kind, and a lot of people do and they work very well for them. So it must work fine with normal size trailers, and I wouldn't hesitate to use one.

The third kind it what I've used most. It has 3 wires (no brake light wire) but it also has a cable you hook to the brake pedal. The farther you push the brake pedal, the farther it pulls the cable and the harder it hits the trailer brakes. I really like the way this kind works, but it does have moving parts so it is more likely to wear out, and it's a lot less common.

And by the way, the second and third kinds will also have the manual actuation as well.

 

Nothing special. There is a 4th style as well.

It monitors hydraulic pressure at the master cyl. And sends equivilant voltage to the trailer MAXXBRAKE is that brand

 

I installed a trailer brake controlled in my truck a few weeks ago and I'm doing another one today. The controller I chose is the 4-wire inertia type as it generally performs better than the simple time based controller. The trucks I'm working on have no pre-existing wiring for a brake controller so I had to make a harness which is easy enough, there is one black power wire that goes all the way from the battery to the trailer connector, this feed will charge the battery in the trailer when it's connected if so equipped. One black and 1 white from the battery to the controller, and one blue from the controller to the trailer connector. The 4th wire from the controller is spliced into the the brake light switch on the brake peddle, this tells the controller when brakes are being applied. These trucks already have a 4-wire trailer light connector so I simply cut that connector off and connect the wires directly to the 7-pin connector as indicated in the diagram that comes with the connector.

 

I had a time based controller and it sucked. You can adjust the amount of braking power and how fast they come in, but it brakes the same in a panic stop as it does if you just barely push on the pedal. Get the inertia based one. If you want top of the line, the T3 by Tekonsha is a good one.

 

I knew they used to make them like that, but was under the impression that no one was willing to risk the liability of having a user open up their hydraulic lines to install the sensor.

That would probably be my first choice of the four kinds, although I liked my cable actuated one too.

Like Bashby, I really didn't like the time-based controller that I had on my '02 (installed by previous owner). I haven't towed a trailer with brakes yet with my '97 so I haven't bothered to figure out what controller it has. If it's a timer it's getting replaced.

 

The pressure reading one is by FAR the best one out there. The new trucks that have a brake controller from the factory are equipped this way.
I will NEVER tow with any other style again. It is a little more pricy than the rest but it WORKS and dam well at that

 

I'm assuming that you are talking about the time-based style, because that's the only style that your statement fits with. Assuming that is true, have you added anything (other than a bunch of smilies) to what has already been said? Yes, you can adjust the amount of braking power and how fast the time-based controllers come in. I already said that. But you can't set it correctly for both a panic stop and a gradual slow down. That's why a lot of people don't like that style.