I am getting ready to haul my first trailer with my 1985 F-250HD. There is a brake controller and 7 pin connector but the controller is disconnected and have not examined the wiring from the connector.

I want to figure out of the controller in the cab is any good or need a new one. Once I get a wiring digram for my model (can't recall what it is at the moment), do I just need read some voltages?

 

Would help if we knew what make & model brake controller you have is. But usually, YES, you'd just have to make sure you have power going to the 7 pin connector at the rear of the truck. I would disassemble the 7 way plug at the rear of the truck to insure of the condition of plug and pins (no rust or crud inside) BEFORE you push power back there and to check wire coloring. See the READ FIRST at the top of the forum page for wiring coding and pinout connections. also here: https://www.etrailer.com/faq-wiring.aspx photo's for all know plugs here too.

Yellow = Left turn
Green = Right turn
Brown = Tail/Marker
Blue = Trailer Brakes
Black = +12 volt source (ie breakaway battery charge)
Orange = Backup/Auxillary

 

Kelsey brand. Photo from one of my interior shots has it in frame.



Interior is surprisingly decent


What modern wiring "features" would be found in newer model trucks that older 80s would not have? Relays seem to be the biggest thing in general.

 

Newer controllers are electronic and pair stopping power to the trailer to the rate at which the truck is deaccelerating, a real advance in terms of smooth stopping action. Older controllers essentially boost stopping power in relation to how long you keep your foot on the brake pedal.

For a starting point in your truck can you tell where the controller used to be connected. it might be worth simply hooking it up and see if it works.

This is not the original Kelsey that is teed at the master cylinder is it?

 

No, from what I have researched and been told is that teeing off the master cylinder is not legal but can find them for sale. I know this one is just electric and wires off the brake switch. I am going to get it wired up regardless when I am done with my move. Don't want to have down time with my truck when it has a job to do.

I found a fancy controller with a rotary push button **** that can be mounted clean in the dash like I want. https://redarcelectronics.com/produc...ake_controller

Spendy but I like the functionality. Not a fan of things hanging off the bottom of a dash. I could even grab a **** from the JY and make that unit look factory almost.

 

You need some kind of load on it to test for voltage output. You can't just push the button and expect power on the blue wire.

Get 12v to the power lead and the brake wire and hook a 12v light to the blue wire. It should light up when you push the manual button on the controller. If it does, then it should be good to go. Finish wiring it up.
Yours looks pretty new, so I don't see a reason for it not to work.

Mid 90's trucks had a plug under the dash for brake controller wiring if it was ordered with tow package(I had a few).

 

Thanks for the tip about needing a load. I have a test light and will dig that out.

My truck was bought from a shade tree mechanic who got it from some guy on a trade for something... I find more butt connectors and electrical tape than wiring