Our 45th trip – hard to believe. Some trips have been pretty short but all of them have been fun. This time we went to Prescott, Arizona for a club rally. This club was established almost 40 years ago as a GMC motorhome club when GM quit sponsoring the original clubs. There wereall of 7 GMCs at this rally – about half of the coaches present – but everyone is still nice and fun to spend time with.
The GMC ran great as usual but we did have a problem starting on the way to the rally. The old “hot start” problem was back with a vengeance. A week or so ago I had all 6 old tires (bought a new tire in Barstow on the last trip) replaced and when I went to leave there I could not start the coach. I thought I had fixed the problem with a new battery ground cable and a new starter solenoid. Well, it wasn’t fixed. About 40 miles from home we stopped to get gas and it would not start again. I would turn the key and there was no sound from anywhere in the area of the engine (the rear suspension air compressor relay clicked in the back). I jacked up the right front and got under with my volt meter and measured voltages as Carol tried starting it. I measured only 8.5 volts on the wire that engages the solenoid. I used a temporary jumper wire to get the coach started and started thinking about how to fix the root of the problem.
The root of the problem is that there are multiple connections, 38-year-old oxidized connections, between the ignition key and the starter solenoid. Each old connection adds resistance to the wire and drops the voltage a little. It finally got so bad that there was not enough voltage to engage the solenoid. The solution to the problem is to use the reduced voltage to engage a small relay instead of the really big solenoid. The relay then connects the battery directly to the solenoid and it now starts like a new car.
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