So my 1986 f250 with a 1995 powerstroke engine and dash and wiring in it is giving me a couple problems. Everything was working good till randomly my brake lights quit along with my hazards, and everytime I try to use either of them the abs light starts flashing 15 short and 1 long. Ive checked all the fuses, checked the brake switch, and all the bulbs. Signal and marker lights work. cruise works but does not cancel with the brake pedal. Its the same problem described in this thread; https://www.ford-trucks.com/forums/1...d-for-now.html

Any ideas?

 

Well, did you check fuse #13 (50 Amp) as that was the solution in the thread you reference. That fuse protects the following ...

1. Aux power socket.
2. Brake pressure switch.
3. Brake on/off switch.
4. Hazard flasher.
5. RABS module.

 

The 1986 cab doesn't have a center stop light in the cab roof, correct? Do you have something to take its place in the '95 wiring?

Do the turn signals work?

 

yes I checked all the fuses and they are all good. and I replaced the original cargo light with the high mount stop light. I had a trailer hooked up with the flat 4 pin connector when it happened.

 

Does it do it with out the trailer? If not I'd be looking at the the trailer wiring on the truck and trailer

 

yes it does it without the trailer.

 

Double-check that BOO switch, and esp. the connector and wiring to it.

Does the 4-wire trailer light connector look damaged/burnt?

 

I will check it again, should I get 12
volts between the wires? the trailer connector is brand new, but I took it off to eliminate it.