Fans wont quit!

[bull4u2me]

I parked my car last night and noticed that the radiator fans didnt quit running. I found that a bit odd, since it was quite cold, and the car wasnt that hot.

Long story short, my battery drained next morning.
Now, each time I go outside, I pop the hood and remove the cooling fan fuses.

What should I do? How can I diagnose and rectify the problem myself? I am kinda tired of meeting my mechanic so often.

[bull4u2me]

How do I know that the thermal fan switch has welded? How would I diagnose that thats the problem?

And probably the dumbest ? ... how do I replace it? Where does it go? I really dont know much about cars... as you can see!\

but thnx for the tip!

[gtroth]

This happens to all of us, I think. Best to do a search here and at clarksgarage.com. There's also a chance it's your fan relay, but that's real pricey so try the thermoswitch first (back of radiator, driver's side, about 3/4 of the way up).

To drive it in the meantime, pull the fuses when you park (#10 and #15, I think, but you better check; I'd check for you if it weren't so late). Some people pull the fan relay instead.

[Moneyguy1]

FR is correct. If you follow the current path for the cooling fan, it gets its ground through that switch and no where else. By reaching down and unplugging it, the fan will shut down.

It will be located on the drivers side of the radiator about 2/3 of the way down. It unscrews, so you will lose some coolant. When you refill the system you will have to "burp" it to get the air out since there is a tendency for air poskets to form in the top section of the engine. There is a fairly extensive writeup for it on the net; Start with the techincal help here in Pelican. You might want to ask the guys here if they would recommend the lower temp switch that turns on the fans at a lower temp and what they think.

If you do not have a Haynes manual, I would advise one. Most of what is in there applies to both early and late 944 models, there are some changes in the wiring diagrams...

[a.n.other]

Yep, definitely the thermofan switch ($10 part). You can just unplug it for now (need to put the lights up and then look on the drivers side of the radiator). You can use the a/c to switch the fans on when you are in traffic and see the temp gauge going up.

I'll also second clarks-garage.com and haynes manual (only in paper version, not web!)

[IceShark]

Clark's also has the testing procedure to bypass the termo switch to make sure that is the problem.

Replacement has a couple items to keep in mind. The switches come with different temperature settings. The originals were 92/102 C. I don't think anyone makes those anymore. The normal replacements are 95/102 C. You can get a lower temperature setting but you may be running those fans like crazy and they suck a LOT of power. I certainly wouldn't go down into the 70 C range. Maybe 87 C for the low speed would be ok if you could find one, but that is about as low as I would go.

Then you need to go pick up a deep wall socket to remove the old sensor and install the new. Get either a 29mm or 1 1/8" socket, either will work fine. And be very careful when you tighten up the new sensor. If you have the stock radiator there is probably a brass boss cast into the plastic end tank you are screwing this into. That plastic is old and brittle and if you sock the sensor down too tight you will fracture the plastic end tank. Then you get to buy a new radiator.

[bearone2]

get the low temp switch if you have or think you have a low temp thermostat.

about $16

[bull4u2me]

thnx everyone for your inputs.

[a.n.other]

Originally posted by bearone2
get the low temp switch if you have or think you have a low temp thermostat.

about $16

but get a regular temp (87/92) switch if you have a regular temp thermostat - else you'll be doing it again (ask me how i know!)