I think the auxillary fan would be useful, if it ever worked... I'm wondering if anyone has ever run a relay/toggle switch to the dash for this fan, for switching on on hotter days. I've been told that it "should" come on when the car gets hot, but my car was HOT and still the fan stayed off... I'd like to get this thing going for some added protection on hot days...

Apparently it seems that it's normal for this fan to come on only when the engine is quite hot. It bugs me that it hardly ever comes on too. I may go ahead and rig mine to come on with a separate relay. Keep in mind that the temp. sensor is supposed to alter engine timing in addition to turning on the fan. You may not want to simply lower the temp sensor trip point since the timing may be changed at a lower than desired temp. I want mine to come on when the air conditioner is on and I am stopped in traffic. I guess it will be on the list of "things to do".

Randy

I'm not sure which engines have the engine cooling fan ignition advance system, but mine does not. Presumably another step to cool the engine. My switch only turns on the fan.

The switch on the radiator which turns on the fan has a temperarture rating. I believe you can get a switch with a lower temperature rating if you want your fan to come on sooner AND have a cooler engine. I looked at import parts specialists and they have different temperature switches available.

I would not. I think if your fan works as designed don't monkey with it. There's always plenty of other stuff we could be monkeying with...
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Paul NW Indiana '89 740 Turbo 103,000

I live in Miami and and it gets very hot. I posted many notes about the same fan and temp gauge the fan works only when the water coolant gets too hot. I changed the temp switch just to make sure and tested the old one. My advice is to get a second temp gauge or thermometer and run the engine you can check the fan operation by covering the radiator and see at what temps the fan comes on. most times the fans work perfectly but we don't know. The temp gauge in the car isn't worth s*#t.
good luck P.S try wiring the fan it so it comes on when the AC comes on

I agree with Paul. Since these fans rarely come on, they have a bad habit of rusting frozen. When you say your car got hot, how high did the gauge go?

Have you verified your ran works by jumpering the switch on the radiator (with key on)? If the the fan runs and you suspect the thermal switch is bad, you can uscrew it and heat it up to 207-216°F (note: almost boiling) and see if it closes. Easier to buy a new switch online for $12...

This is how it is designed to work and I assume they had a good idea when they designed it. Mine rarely comes only on - only when the ambient temp is high, AC is on and in traffic.

If you really wanted to, you could run a pair of wires from the switch to the dash and exercise the fan.
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Paul NW Indiana '89 740 Turbo 103,000