Here's an odd one for you guys.

Last summer, I re-filled my A/C on my 84 300D (Euro) with more R-12 (knowing full well that it'd leak out.. but damnit, I was hot). After hooking it all up, I noticed something strange..

..the Aux fan would go on at a certain temperature (normal), and after turning the car off, it would *stay on* for a while. Is this normal, for that fan to cool off the car, even when the vehicle is off? Or is this a bad temp. switch / relay / wiring issue?

The A/C is an aftermarket system in this vehicle (uses a volvo compressor, but everything else is standard 300D parts, btw. I don't think my US 300D ever did this, though I could be wrong. So.. am I just going insane, is this normal? Or do I have a problem?

I don't know if the behavior is "normal", but it is a very good behavior. The engine coolant will auto-circulate, the hotter it is, the longer it will auto-circulate. The aux fan running after you shut engine off, especially if you were running the A/C will keep hoses / radiator from being over-stressed, as well as keep the pressure relief on the radiator cap from popping & losing coolant.

The schematic in my Haynes manual suggests that the aux fan should work only with ignition ON. However, maybe whoever wired your system changed it to work even after you have turned off the car. This can be a good thing and I know that I've run across cars in a parking lot with the engine off but the fan still running. I suppose as long as it doesn't stick ON and drain the battery it is OK.

__________________

"Buster" in the '95

Our all-Diesel family
1996 E300D (W210) . .338,000 miles Wife's car
2005 E320 CDI . . 113,000 miles My car
Santa Rosa population 176,762 (2022)
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"Oh lord won't you buy me a Mercedes Benz."
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