Need wiring diagram for the towing harness showing location of connections to source of signal

SOURCE: Wiring harness diagram

Your question is not clear, 2002 trailblazer has a towing harness, in order to find each wire, use a ohmmeter and try out each application.

In case of male harness of a camper you can test it with 12 volts in each wire looking which light is on and if it is different position cut wires and make similar wiring

SOURCE: wiring diagram for 1988 ford f250 4x4 460 cu in

Try having a look here:

http://www.autozone.com/shopping/repairGuide.htm?pageId=0900c152801cd403

Hopefully this gives you what you need. If not, I can keep searching or see what else we can do.

SOURCE: 2003 Dodge Ram 2500 diesel 4x4 wiring diagram

TPIM PROBLEM , MUST HAVE COMPUTER FLASHED AT DEALERSHIP

SOURCE: LEFT TRAILER TURN SIGNAL DOES NOT WORK

I have seen once before that the fuse box was bad on a 2003 Dodge 3500. I had power in and nothing out. We had to replace the box. Not cheap! Hope it is simple like a loose connection though. I think I had to pull the inner fender on the drivers side to access the bottom of the fuse box. Pain in the ****, but...

SOURCE: Tow bar trailer socket wiring connection point to car wiring?

The connectors for towing wire harnesses on foresters are generally on the passenger side, below the rear taillight inside the cargo space. some require pulling up the foam block that is between the spare tire compartment and the taillight. Check where you replace the tailights from inside the car, if there isn't a matching connector hanging out there, check around the spare tire compartment, see if you can remove the carpeted foam block next to the compartment and find the plug under there.