Alright, so basic question....measuring my rear running lamps, one side is 11.8v, the other side is .11 volts at the bulb. The low voltage side measures 4.1v right at the body processing module. So I'm thinking a short...right? Current leaking to ground? I already tested the cable from the rear running light bulb as far as the main harness near the rear seat, so now I need to trace the main harness from the trunk to the BPM and I don't know how to do that.

I do have the JTIS manual; does that show the routing of the wire and where it goes (under the rear seat, under the door jam...where? Or do I replace the whole wire and how?)

I mean, if I literally just snip the wire at the BPM and at the bulb and run it out the window to the trunk I could make it work. :P But how should I really do it?

 

If you are confident that it is a wire inside the harness sheath is shorted you are going to have to run a new one. Lots of us have had to disassemble the interior to replace the convertible top latch hoses which is a lot of work. Look for damage as you expose the harness. Perhaps it is repairable rather than running a new wire along the sheath.

 

The harness location is shown in the electrical diagrams. Download location shown in
the stickies.

 

I tested the wire right at the gas tank where it disappears into the main harness and it was still at .11V. So I'm losing ~4 volts from somewhere around the BPM to the gas tank for my rear running light.

I'm hoping that the BPM is putting out good voltage but that it's getting shorted to ground. Any other obvious places that I should look? Seems that the most likely location would still be near the gas tank for a short.