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Discussion Starter #1
Any suggestions for a cooling fan that seems to spin way too long after the engine is shut off? This happens during the very hot months in Arizona. Even though it's scorching, I've been told the fan should run for no more than five to 10 minutes. If I don't use my battery cut-off switch the fan will eventually kill the battery. Is there some type of timer that's misbehaving? It's an '89 Quad.
 

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The 1990-93 (-94 in US) euro spider S4 fans stop as soon as you turn off the ignition key?(I sometimes leave the ignition on for a minute on really hot days....not much of those in Germany at the moment:)).... was/is it not the same with the 89 model (much the same mechanics, I thought?)
 

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L-jet cars have a sensor in the fan shroud that activates the AC/auxillary fan when it senses a certain level of hot.
It's wired in such a fashion that it can run the fan even if the key is turned off.

It's entirely plausible to disconnect the sensor at its harness whip plug.

This will allow the fan to come on normally with the AC (test it of course) yet prevent the fan activating via the sensor all together, so in turn, stop its ability to run by itself.

Its questionable as to whether it does or doesn't help with heat soak post shut down, and honestly I can't see that being too big a deal anyway as every version prior w/o AC didn't incorporate a secondary fan to deal with it.


If you don't want to actually lose the ability of the fan to come on while in traffic, you could incorporate a switch into the sensor wiring so that when the switch was on the fan would operate via the sensor, and when the switch was off it couldn't come on.
This could also be accomplished via the relay that is associated with the sensor and rewiring it a bit so that it couldn't activate w/o the key being on.

There's actually a lot of ways around it, up to and including getting an adjustable sensor so you can at least tweak its on/off parameters a little bit, or even picking up a more efficient fan, but that in itself won't stop the fan from running X amount of time post shutdown because the temps have to be brought down to whatever level to get it to switch off anyway.

The only hard~n~fast way would be the disconnection of the sensor, or incorporating of a switch or relay rewiring to get it so that it could not actuate when the key was off.
 

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fan running on

I had a 1985 SAAB 900. The fan running after shut down for a few minutes was a feature. A failure in a relay was a common cause for the fan running continuously.

The sensor on my 86 has only ever been held in place by one screw to the upper edge of the fan shroud on the passenger's side. Could yours have fallen off or removed and not put back and be someplace that stays hotter, longer?

Wayne
 

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From what I saw in the weather report for Phoenix yesterday, the fan SHOULD run all day. Spend your summers in Montana like all the other good AZ citizens.....

Robert
 

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Discussion Starter #6
Thanks for all your input...very helpful. To 60sRacer: It was hotter in Minneapolis than Phoenix yesterday!
 

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At home I raise the hood to help lower the temp. The longest I have scene it run is approx 15 minutes. But I have not been in 110 temps, that is way too hot!
 
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