Trailer plug has no lights

Stroken7.3 · Jul 10, 2011

My factory 7 flat trailer plug isn't working, I do have trailer brakes but no lights at all. I checked my power distribution box fuses 1,3 and 4, thoses fuses have no power on either side of the fuse and I also did a visual check on them and they weren't blown. Does the key need to be on to send power to those fuses? All my truck lights are working fine. Thanks for any advice.

Tom S · Jul 10, 2011

At least on the OBS a few of those are relay controled in the underhood fusebox.

Stroken7.3 · Jul 10, 2011

Thanks Tom, does the relay send the power to those fuses?

Tom S · Jul 10, 2011

Not sure on that but I think I have the SD wiring diagram uploaded in the library so I bet that might be helpful for getting this figured out. If it was OBS I have the books here at my desk.

Stroken7.3 · Jul 10, 2011

I'll check there and see if I can figure it out, I'm not good at wiring at all.

Stroken7.3 · Jul 10, 2011

Just went and turned on my lights and flashers and the fuses 1,3 and 4 have power, they have to be activated by the light switch, turn signal and brake switch. I'm sure I just need to rewire a new plug.

JLDickmon · Jul 13, 2011

On the SD's, there is a couple relays behind the dash (under the radio) that need to be installed.. I know they come in the kit.. they go in the same block the turn signal relay (the blue one) is..

Stroken7.3 · Jul 14, 2011

My relays have been installed from the day it was new. I think my original plug has corroded wires, as it used to work great.

JLDickmon · Jul 14, 2011

Stroken7.3 said:
My relays have been installed from the day it was new. I think my original plug has corroded wires, as it used to work great.

that happens..
I used to see it all the time when I was wrenching, as I specialized in electrical issues.

You trailer plug leads back to a square-ish 8 wire connector that breaks out of the main harness up over the spare tire.. I've seen lots of corrosion creep in there, too.