Izzy

On a later model 944 (944S2), what do the different lines on the temp gauge correspond to, in °C? My fan switch seems to be bad, so I just ordered a new one, 92/102°C (pelicanparts made it seem like it was the only one you're supposed to use, hell they even told me that over the phone), and ideally I'd like fans to come on and keep the temp gauge around the halfway mark, but I have no idea what temperature that is. Should the 92/105 be sufficient, or should I go lower? I have NO idea what temp thermostat I have in there, its brand new, and I also don't want a fan switch so low that the fans run constantly. Any suggestions? Advice? Free money?

RedlineMan

Hey;

It was always my understanding that the fans kicked in at 217F. In most cars, that should correspond roughly with the 3rd mark. However, the function of the later model fans has always been a mystery to me. I have never found anyone that truly understood all the various modes that they operate in. The early cars are simple. Car gets hot, fans run. Turn on AC, fans run double speed. Turn off car and 1 fan just trickles for a while. The late cars have so many different modes it is a complete mystery. They seem to have a mind of their own.

Not much help, I'm afraid.

Charlotte944

OK, here's the scoop:

Early cars:

Radiator hot, ignition off, ONE fan (driver side) runs in SLOW speed until radiator cools.
Radiator hot, ignition on, BOTH fans run at HIGH speed.
Ignition on, A/C on, both fans run at HIGH speed.

Late cars:

Radiator hot (first or second temp setting), ignition off, BOTH fans run at slow speed.
Radiator hot (first temp setting), ignition on, Both fans run at SLOW speed.
Radiator hot (second temp setting), BOTH fans run at HIGH speed.
Ignition on, A/C on, compressor discharge pressure in "normal" range, BOTH fans run at SLOW speed.
Ignition on, A/C on, compressor discharge pressure "high", BOTH fans run at HIGH speed.

Izzy

Sweet, someone else in Richmond! What kind of fan switch would you put in? Like I said, I don't want the fans to run all the time, but I also don't want the car to run too hot. Is my 92/102 sufficient? Or maybe its not my fan switch at all, my fans basically aren't turning on at all unless the A/C is on, the car will overheat otherwise.

michaelathome

Izzy,

You would have known that Cliff was there if you had read my locals guide. Been trying to get that disc out to ya but can't seem to make time. Its sitting in my trunk labeled and ready to go. Just gotta get to the USPO to take care of postage.

Michael

Charlotte944

As long as the rest of the cooling system is OK, a stock switch should be more than adequate. If the car was in the desert, or farther south like Florida, then a "low temp" switch would be better.

The easiest way to test the fans is to disconnect the plug at the fan switch and jumper the connections at the plug. If you can get the fans to run by jumpering the plug, then just replace the switch. When you replace the switch make sure you replace the fiber washer, or the sucker will leak.

If you want to test the switch, just put it in a pot of hot water and use an Ohm meter to see when the temp switches close.

If the switch tests out OK, but the fans do not run when the wiring plug is jumpered you could have a problem with either the wiring or the fan relay.

Izzy

Might as well replace this first and single one component out, especially since I already have a switch.

cruise98

The late gauge readings in Celsius are as follows:

Top of lower white block is 60
Bottom white line is 80
Upper white line is 100
Red is get out your wallet too hot

Your car should run between the two white lines. If everything is working properly, it will run around 80-90 most of the time, unless you are sitting traffic, and it may go up to 95. The fans should be going full blast by that time of course.

fezz

Cliff, hope your doing well and meeting a few of the VA guys. We miss you here in Charlotte.