Help with trailer brake
 

Is anyone familiar with the set up of this trailer brake. Everything is hooked up accept for the two wires in the picture. It is hardlined into my proportional valve and the green wire is hooked up too. My truck is completely stock electrical wise other than the hitch and connectors. They guy I bought the truck from use to tow his race car and trailer. It very well could be hooked up already. I just dont know if the two wires that are disconnected need to be hooked up to anything. If so where do they hook up too. The plug in the rear of the truck works. Like I said it very well could be good to go. Just trying to see if the vast knowledge on this site could help me with confirmation. Thank you.

Re: Help with trailer brake
 

I am interested in this as well. Mine is mounted to the steering column and it has the same line to the prop valve.

This is my theory, the line to prop valve moves the lever on the controller when you step on the brakes. That creates an electrical signal that goes back to the plug at the rear. That activates the electric brakes on a trailer. This is just my theory and if correct would indicate you need some kind of power back to the plug. Mine has wiring that runs along the frame rail to the rear and taps in at the back of the harness. I can get pictures of all of this if you need it.

Re: Help with trailer brake
 

I have two lines that run my frame rail also. I will take pictures and compare them with your today. Currently, every time I step on the brakes that handle moves To the right. I don’t know how to adjust anything and I can not find info on such an old model. Thanks for your input. I think your theory is correct makes sense at least.

Re: Help with trailer brake
 

I only use RF wireless electric brake controllers. So, my knowledge on the old school controllers is limited. But, I would think you need constant 12v into the controller and variable 12v out of the controller to the 7-pin (is it the blue wire) trailer plug. Of course grounds are needed as well.

The flat four pin trailer plugs do not have provisions for electric brakes. If your trailer has brakes and a 4 pin connector, then the trailer brakes are hydraulic surge brakes (best for boat trailers).

Re: Help with trailer brake
 

Old Kelsey Hays brake controller. Was operated by fluid from the braking system and the wiring is +12v to the controller and the blue wire (I think) goes to the trailer brakes. I believe there may also be a ground wire or they use the mounting and brake line connection as the ground. Should glow red when stepping on the brake or manually moving the lever on the front. I don't recall how to adjust the sensitivity. Here is a link for a copy of the manual http://67-72chevytrucks.com/vboard/s...d.php?t=782914