What gives? I never have back up lighting because the fuses are always getting blown. I have to rewire my trailer plug and would like to get this fixed.

 

The trailer plug and its wiring would be the first place I'd start looking for a short.

 

Yup, you got a dead short in mine and blew the switch on the trans.

 

It is a simple matter to isolate the factory REVERSE signal wire at the plug in the transmission.

There should be a KEY-ON=HOT wire and a "cold" wire that is energized when REVERSE is selected.

Follow that "cold" wire to a handy place where it can easily be cut and spliced to longer wires that lead to a relay.

Then, simply relay the REVERSE lights the same as you would relay any other system.

If you don't find your short-circuit problem during this relaying process, it will now be easier to isolate the problem; plus, you can now connect some BIG REVERSE lights with no worry of over-taxing the wimpy factory system.

 

I had to replace the 7 way anyway and get my trailer wiring ready, while doing this i found that the PO had ground at the center terminal. I switched the ground to the 1 position and put whatever had been on ground to center plug. OK at the 7 way, I have 12 volts at the tail, brake, and hot feed. LT and RT are not reading voltage. In truck right turn indicator lights solid with tail lamps on, but works when turn signal on. I pulled right tail light, PO tapped into taillight feed (black w yellow tracer) a two foot long piece of 16 gauge going no where. What is up with this, trying to put more resistance, why. I got too many variables going on right now, I wonder if I should completely disconnect trailer harness and put everything back to factory, make it all work and then put 7 way together. Oh and still no back-ups, I put in a 20 amp fuse, fuse is good now no backups, I prob. blew the switch now. Any wiring experts close by?

 

If you are trying to work with someone else's wiring rat's-nest, then YES, it would be best to just cut out anything that is definitely not factory and start over.


To me, wiring is as natural as ABC; I just can't fathom why it is such a mystery to others.

Another interesting observation is that it is rare indeed to find a "mechanic" who makes his living as a mechanic that will take any pains at all with proper wiring technique; all I have ever witnessed, their wiring tool kit consisted of a dull pocket-knife and big sticky wads of black tape.