Electric Cooling Fan Won't Stop!

[aplcr944S2]

on my 89 S2 and it has drained my battery. When I am looking down into the engine at the cooling fans. The one on the left (passenger side) keeps running. If I turn my lights on to position one it turns off. Weird...Anyway now my battery is dead and I cannot figure out how to get the fan to quit going. Any suggestions?


Cory

[67l60]

pull the fuse for #1 fan

replace thermo switch on radiator , its like 15 bucks

check fan relay and replace if needed , its expensive

reinstall fuse

[Techno Duck]

More than likely you have a problem with the relay if only one fan stays on. You can easily test the fan switch by pulling the connector off and jumping the 3 pins together in pairs. Jumping pin 3 and 1 together should trigger high speed, and pins 3 and 2 will trigger low speed. Both fan's should turn on during this test.

But like i said, more than likely your problem is the relay. I would try to find a used one, new relays are about $150 from Porsche. You may be wondering why on earth a relay costs $150..well its because Porsche had the bright idea of making something that should be fairly simple, extremely over engineered! For giggles, take the cover off the old one and you will be amazed how overly complicated it is, its literally a computer circuit board that looks more advanced than my laptops motherboard on the inside. You can also inspect all of the solder joints for cracks and attempt to repair it.

[gtroth]

I drove around like that for a couple of weeks unitl I got to replacing my thermofan switch (that's what it was in my case). Just pulled the fuse at every stop - no big deal. Some people pull the relay, I hear.

Borrow a good relay if you can to know which part is the culprit.

[aplcr944S2]

I pulled both fuses so that I could charge the battery. Tonight when I parked the car the fans were going. I went out about a half an hour later and they had stopped. Interesting to say the least. Does anyone know how long the fans are set to run after you have driven the car?

Cory

[67l60]

they will run ,until the cars water temp reaches it low point on the thermo switch i think mine at 89.2

[Techno Duck]

Low speed fans will run until coolant temp in radiator is lower than 92c. That is with the car on or off. The high speed fans only kick on when the ignition is on and temp is higher than 102c.