One Misplaced Wire

Last summer, we had our motorhome at Hilltop RV in Escanaba for several weeks to have some work done. When they called us to say it was ready, we drove the car down, paid the bill, hooked the car up to the motorhome, and took a short trip to Lansing. On a stop for food somewhere along US2, a fellow RVer waved at me in the parking lot, and said the lights on the car were blinking on and off. I filed that information away and continued on the trip.

Later that fall, we took another trip with the motorhome to West Virginia, and planned to tow the car. The story of why we didn’t take the car is talked about in detail HERE.

This spring when I got the motorhome out of storage, we planned to leave fairly quickly on another trip to West Virginia, so I worked my way through the various projects… emptying the antifreeze from the water system, changing the engine oil and greasing the chassis, and the car lights. I’d saved that one for last because it was the one I wasn’t sure about. I took apart the left rear taillights to see if I could find anything wrong with the wiring there. I did find one connection that was not up to snuff, so I took it apart, cleaned it up, and wire-nutted it back together. After that I clasped my hands together and said, “oh please oh please oh please.”

Shortly thereafter, we worked through the process of hooking up the car. Everything went well until the time to check the lights on the car. Just like last fall, there were no break lights, turn signal lights, no nothing. Shoot. I got the meter out and started working my way through the circuits. Through some faulty reasoning, I became convinced that something had happened in the wiring of the car that had caused the lights to fail. Unfortunately, the kit to make the car lights work properly was expensive, and the wiring required to make it all work was beyond my capability. Then I had another idea.

When we bought the RV, we had set the pickup truck up to be a master source for the car lights too. So I hooked the pickup up to the car via the RV cable to test the theory that the problem was in the car. The results astounded me… everything worked! I wiggled things trying to get something to fail, but the car lights mimicked the truck lights perfectly. So the problem was not in the car. Now what?

I decided to call the folks at Hilltop RV in Ishpeming and throw myself at the mercy of the service department. A very nice man answered, and I poured out my problem to him on the phone. He listened courteously, asked good questions a couple of times, and then suggested I had a grounding issue. I had thought the ground for the lights was transmitted through the metal in the towing apparatus, but he said no, that the lighting system for the car was transmitted through one of the pins on the 6-way connectors between the two vehicles.

This scrap of information gave me a fresh perspective on the problem. I looked at the way the truck connector was wired, and compared that to the wiring on the connector on the motorhome. You guessed it… there was one misplaced wire. I removed the connector from the motorhome, changed the one wire, hooked everything up, and voila, it all worked! We shifted into high gear, loaded up the vehicles, and got on the road by mid afternoon.

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