Thanks, I'll try that tomarrow. Why would it be that the one on my wifes Yukon is ironiclly not working either?? Also I bought my truck with out the electric brake setup but went to Ford and bought the factory setup with wiring harness too. Mounted it like it was from factory. Don't know if that even matters? I have also noticed that my electric brake power is not as strong on even level ten as is a couple of friends trucks that are also used on the same trailers. Maybe this all is from the same problem????????? That is why I posted it on this form b/c I have been extremely impressed with all the knowledge and help there is!

Thanks for responding, Russell

 

Russel, is the brake controller the same brand? That might be why the strength is different.

 

I also have problems with my 7 prong plug not getting any type of voltage. I have checked and replaced circuit 107 and relay 301. My lights on my truck work, but I can't get any activity at the trailer plug. Could the wiring harness have come loose? I use my truck in very rough terrain. Where can I check the harness connection if there is one. It has to be something that affects all connections to 7 prong plug. Thanks, Shasto

 

The plug should be at the rear of the truck where it plugs into the harness. What year truck and what model are you working on?

 

I have a 2005 F-250 Super Duty gas. I went to the dealer to ask where the common connection the the plug harness was and he told me it is on the left wheel wall. I have power there but that may be what is feeding my truck lights. They do work on the truck, but not on the plug. What would happen if I tagged on to the tailights like we use to do in the old days? Not sure if there is something else on this circuitry. Another guy told me it could cause my truck NOT to pass inspection here in Texas where it is done with computers. I don't know what the difference would be, or what other circuitry would be running off trailer harness. I have already checked the relays 107 and 301 and the pertinent fuses ID'd on the owners manual. They are good. Just has me stumped. Thanks

 

Nothing bad would happen if you tapped into your truck's regular lights. If you had a problem with the trailer lights, it would blow the fuse to your regular lighting on the vehicle, but that's about it.

One other possible problem though. If you tap into the brake/turn lights, your flasher may act funny. Remember in the old days you had to get a heavy duty flasher when you towed with a trailer? Same thing applies, but I would try it first, the new trucks use a different kind of flasher and it might work fine.