f800 w/air brakes need to install electric brake controller

I have a '98 ford f800 dump truck, w/air brakes, 33k gvw, 8.3 cummins and 6 speed allison. need to pull a trailer with electric brakes. I am trying to find a line or switch that can act as the feed to the prodigy controller. so far all of the feeds I have found that give 12 volts when the brake peddle is pressed , also give an intermittant feed when the turn signals are actuated. Does anyone know if there is a brake light switch that I can use or do I have to install another air actuated switch in order to install the controller. I only use these units on the ranch and sparingly, so I won't be buying the more usefull air brake type trailer. The belshe triple axle tag is paid for and plenty strong.
thank you in advance.
rick roberts

I think you will have to investigate the controller. I wired my F800 like this> one wire to Ign switch,
one wire to the stop light switch one wire to the rear (trailer brake) So you will have to find the
stop light switch and that could be anywhere mine is on the brake treadle under the floor. But you
need the instructions for what color wire goes where. Far as I know all controlers have an intensity
dial to dial in the amount of braking. Thats been working since 1988 when I bought the trailer.

Thanks, I will look at the peddle area again. It looked like there was 2 air switches and both were hot all the time, but I will look further for another switch. I understand the description you gave, but I am having trouble with where to hook to the brake switch for impulse signal to controler.

What you're looking for is a switch that's hot all the time on one leg and the second leg goes hot with service brakes applied. ( but not parking brake) Get a good adjustable controller like the Tekonsha ones and beware of the cheap ones. The cheap ones that can be mounted at any angle are time based and can really burn up your trailer brakes as well as not applying them when needed. Example 0-0.5 seconds they apply 20% braking, .5-1 second you get 40 % braking, 1-2 seconds you get 60 % braking and finally after 3-4 seconds full braking. So in a panic stop you're screwed and on a long decent, the trailer brakes are trying to slow the whole rig.

You might have to put a diode in line with the brake wire. I forget the exact arrangement but I had an International that would back feed the brake light switch when the 4 way flashers were on. I got mine from the place where I buy my brake controllers (Weaver Distributing 1-800-WEAVERD). Sorry I can't remember the particulars.

Orchard Ex said:

You might have to put a diode in line with the brake wire. I forget the exact arrangement but I had an International that would back feed the brake light switch when the 4 way flashers were on. I got mine from the place where I buy my brake controllers (Weaver Distributing 1-800-WEAVERD). Sorry I can't remember the particulars.

Click to expand...

I was going to try to do just that, as the diode could be placed in the line going back to the lights. Then place the controller feed wire in between the diode and switch terminal. That way the lights would still get the current from the switch, but would not feed current back from the bulb (with blinkers on) to the switch where the controller feed was now attached. I probably explained that poorly, but i think that is what you may have been speaking to.
rick

Well, if its a proportional controller and its not set to a boost setting, having the brake light wire hot won't do anything to the braking unless you're slowing down. The good ones requre decel and brake light to begin sending current to the electric brakes.

Also, in your wiring to your trailer, use at least 12 ga wire, I get mine from the marina or online marine supply, 2 wire 12ga in a jacket, long trailers have a lot of wire and there's a bit of loss, each brake wants 3-5 amps or possibly more, the better the voltage at the wheel, the better the action.

fast_st said:

Well, if its a proportional controller and its not set to a boost setting, having the brake light wire hot won't do anything to the braking unless you're slowing down. The good ones requre decel and brake light to begin sending current to the electric brakes.

Also, in your wiring to your trailer, use at least 12 ga wire, I get mine from the marina or online marine supply, 2 wire 12ga in a jacket, long trailers have a lot of wire and there's a bit of loss, each brake wants 3-5 amps or possibly more, the better the voltage at the wheel, the better the action.

Click to expand...

It is a proportional, and that had not occurred to me. It may not be needed to add the diodes. I have them now but I may try the connection first without and see how the brakes work. thank you

why not use something like this
Hayes Air/Electric Brake Controller

E-mail this product to a friend






Part Number K1100400B-278614
The air actuated electric trailer brake controller provides smooth brake actuation. The electric brakes on the trailer operate off of the air brake system of the tow vehicle. When the brake pedal is depressed, the application of the electric trailer brakes is proportional to the vehicle's brake pedal pressure. Comes with two way check valve, needed for installation.


Price: $199.95

well, I used a diode inline to the lights. I then took my input from the switch, and it works perfect. problem solved.

I already had the controller, or I would have tried the hayes unit . I had read about it earlier, and it looks well designed.

thank you all for the suggestions and advice.
rick roberts