led

OK, so the fans are supposed to stay on even after the car is turned off. What can keep them from staying on? I've been blaming it on the relay but haven't found one on ebay yet and I don't want to spend $100+ on a new one to later find out that's not the problem.

IPSC

Ok what turns the fans on and off is the relay. The relay is controlled by something called the fan switch. It is a plug that screws into the radiator just below the top water hose. If you can get to it and unplug the electrical connector, simple test to see if your relay is good is to jump the contacts. Simply take a paper clip (a large one, it has to carry 20 AMPS for the high fan setting) and BRIEFLY jump the center contact (on the electrical cable and not the fan switch) to the two outside contacts. The low fans should run (can’t remember which contact) the opposite should run the high fans. If your fans keep running for a long period of time after you shut the car off it is probably the fan switch. This has the potential to strand you some place as it WILL run your battery down. Don’t ask me how I know this,

IPSC_GUY

944Play

<a href="http://www.clarks-garage.com/shop-manual/cool-01.htm" target="_blank">Fan Operation and Troubleshooting</a>

Scroll down for instructions on later cars. HTH!

led

Thanks guys! I still have to check my car using the instructions on the clarks garage site. FWIW, if I leave the ignition turned on (car not running) the fans will eventually turn off so I take it the thermoswitch isn't bad, or is it?

gleamingred944

The rad fan has two speeds, and the low speed makes so little noise you can miss it. When you turn the ignition on, does the fan immediately come on high speed? If so, you have a stuck temperature sensor, and the low speed fan will wipe your battery out after a couple of days.

Been there, sone that ...

Paul C 944

I got a fan rely at dc automotive for 25 bucks! 1-800-579-2410.(thats the expensive $175 one) <img src="graemlins/beerchug.gif" border="0" alt="[cheers]" /> <img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />

led

gleamingred944
The fans don't automatically turn on with the car or when I turn the ignition. They start after the car warms up, also they stop a while after the car is turned off, when it cools down a bit. However, they only do this if I leave the ignition on. So, thermoswitch is out?

Paul C 944
new or used? do you know if dc auto ships via USPS? I'm waiting on a friend with a paypal account so I can get a used one for $30 shipped. Shipping makes prices for what I order get high. Since not everyone ships Priority to Puerto Rico and ground isn't available I end up paying quite a few extra bucks on fedex or UPS plus 6% tax. I don't have to pay tax on anything I receive via the USPS... go figure!

Pilot Dave

Looking at the wiring diagram of an '84 944, if the fan is on with the ignition on and not on at all with the key out, you might have a bad resistor.

<a href="http://www.pelicanparts.com/944/electrical/944_84_AC_2.jpg" target="_blank">http://www.pelicanparts.com/944/electrical/944_84_AC_2.jpg</a>

Follow the wire out of fuse 3 and you see a wire going to the relay and another thru a resistor. The resistor is there so the fan runs at a lesser speed when the ignition is off. If the resistor is blown then there will be no way to get power to the fan without power to the relay.

I'm not sure where this resistor is but if you run long leads on a multimeter in ohm mode, one on the fuse and one on the red/black wire on the cooling fan, you should get a closed circuit with some resistance. Infinite resistance means blown resistor.

led

I agree with you on that, but my car is an 86 and I think there's a different setup because it doesn't have the additional fuseboard where fuse #3 lives. That would make at least the diagram different.