94' F250 XLT regular cab 4wd, 351W/5spd

I found that my truck has the connector under the dash just like it's supposed to for the electric trailer brake controller. I started looking over the factory wiring diagrams to see where I need to tap into for the trailer brakes at the back of the truck, however, and found that I do *not* have the associated relays underhood in the fuse block to just be able to plug and play.

Has anyone else run into this and found that this connector is basically useless or can I at least use it for a GND and STOP connection to the controller?


Thanks,

Bryan

 

Does your truck have the factory 7 round trailer plug on the back?

 

No, when I bought it, it just had a ball on the bumper and a T-connector that came out to a 4-flat under the bumper to power the trailer lights when I bought it. I've since checked it with a voltmeter and it appears that the Stop Lamp switch and ground are the only two wires that seem to be live, but no +12V supply. There is a 5th wire on the car side of the harness that isn't on the Tekonsha adapter...someone said that was for illumination but I didn't turn the lights on to check it.

I'd like to tie into the lines that come to this connector for the trailer brake signal as well as +12V but I'm not sure where they end...I just see them go up under the dash. The factory wiring diagram has been a bit dissapointing in thie area as well. It would be nice to avoid having to put another hole into the firewall to run the wires.

 

I'd say it's probably be best just the hardwire in the brake controller. You'll first need to get a 7 round connector on the back. Then it's simple from there. One wire to the battery, one back to the 7 round, one to the cold side of the brake switch (only has power when you head the brakes), then fround it and your set. Make sure you fuse all the hot wires. An hour of time and your good to go.

 

Bryan -

If you do wire it yourself, the power wire from the battery to the controller should be protected by a 25amp auto-reset circuit breaker, not a fuse.

Steve

 

Steve is right, I forgot about that.