1989 560SEC radiator fan starts on cold engine.
07-09-2015, 03:16 AM
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I own a 1986 560 SEL and a 1989 560 SEC
1989 560SEC radiator fan starts on cold engine.
So I have a 560 SEC with 160,000 miles. I just recently installed a new fuel/air mix valve and the idle control valve. The car is running great now, but I just noticed that the radiator fan starts, engine cold, as soon as I turn the ignition switch on (not the engine) then it appears to work properly. My a/c has not worked since I bought the car so I haven't touched that system. Any ideas as to how to diagnose and repair this problem will be greatly appreciated.
07-10-2015, 01:26 AM
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I own a 1986 560 SEL and a 1989 560 SEC
Follow up
So I had a bad connection at the temperature sensor on the thermostat housing. The negative wire was severed from its connection. so now the auxiliary fan stays off when I first turn the ignition on though I don't know yet if it is working properly. Today was a very cool day in southern CA so the engine bay did not overheat at all. So hopefully this is normal otherwise it will be back to square one.
