Bought my 2003 GX last year. The car was not prep for towing. Installed a factory hitch, towing wiring harness that plugged into pre-existing connectors near the spare tire, and the towing tail relay. After all this, I can't still get my boat trailers' brake and turn signal lights to work. Had my trailers' lights checked and everything checked fine. The dealers in California are useless. They can't figure out the problem unless I'm willing to commit $600, which I don't want to. Anybody know what I need to do? Am I missing more relays? Please HELP.