Ballast resistor-blower fan

[Rtarh2o]

I have read the posts on fan speeds and cleaning the ballast resistor. Here is my problem, my fan only runs on two speeds, low and high. The bigger problem is that I can hear noises coming from the fan, like there is a small amount of power going to it and the fan is turning slowly when the car is off. I am actually glad to have found this because it solves the battery drain problem.
I assumed both problems were being caused by corrosion on the ballast resistor so I pulled it and let it soak in vinegar for a couple hours. It looked pretty clean to begin with and there weren't many bubbles if any as it soaked. After doing so I dried it with compressed air and reinstalled it, same problem, no change?
I checked the price of a new ballast resistor and I am hoping it may be something else!
Any ideas?
Rusty

[geofen8036]

If the fan is turning with the ignition off? You should be looking for a short. You might want to check and clean your grounding points just for good measure. Have you checked your input and output voltage at the fan speed switch? Low, medium and high. Could be a bum switch. You can check the resistance across the ballast to verify if it's good. I don't have the parameters.

[Rtarh2o]

I am not sure the fan is actually turning but I hear a noise coming from the fan when the car is off. When I pull the connector for the ballast resistor the noise stops, I was assuming it was probably a short in the resistor, didn't think about the actual switch?
How would I test it?
Rusty

[CKniht90]

wait... When I drive my car to the point where it gets hott, then I park and get out.. like 30 sec later I hear my fan kick on. I know I have a thermo fan switch that turns on earlier then normal. Could that cause that? Is my fan suppose to kick on high when I park and leave my car after driving it for a while. I always wondered that. I dont have any battery drainage or battery problems though.

[Rtarh2o]

CKniht90, I think you are talking about the radiator/cooling fan, I am talking about the blower for the heat/AC inside the car. It is in the windshield cowling and even with the car turned off I can hear a noise coming from it until I pull the connector going to the ballast resistor?
Rusty

[geofen8036]

You can also check the switch by checking resistance across each setting. It still seems worrisome that your have current there with the ignition off. Pulling fuses from one circuit at a time will help identify if you have bleed over from somewhere else. Happy hunting. I am assuming you have a multimeter. If not, a simple meter is inexpensive and a must.

[CKniht90]

oic.. I noticed that mine does that too... but only with key in. That little fan I seen is under that plastic covering by your windshield under the hood. It kicks on more when I push the button above the blower defrost button. I always thought that fan was for fresh air circulation? Or am I guessing wrong? But I have never had it run after I took out key. So is there a wire for it that is sort of a remote wire to make it turn on? or a relay or fuse? hope this helps if any..

[mattdavis11]

Is this an early car or a 924s?

[Rtarh2o]

CKniht90, interesting about yours doing that only with the key in? My car is in my shop (has been for months now) so the key is always in the ignition in the off position, never thought anything would be activated by just inserting the key?
I will check that when I get home this afternoon.
I haven't checked to see if the fan is functioning properly after the cleaning, I just assumed that since it didn't fix the other problem it probably didn't help the fan speed either, will check that too!
Rusty

[CKniht90]

with key in.. and turned over to the right once... twice turns on the dash.. 3 times starts car... if that makes sense.

[Rtarh2o]

Checked it yesterday, mine does it with the key in or out. Still haven't checked the fan speeds but will this weekend, trying to get a no start issue figured out right now then I will get back to the little stuff.
Rusty

[Rtarh2o]

Here is the latest on my blower problem.
I soaked the ballast resistor in vinegar now I have all four speeds on the blower but there is still a problem, the fan is getting a bit of power when the ignition is turned off, I can hear what sounds like the fan turning at a very slow speed. I removed the blower relay, it stopped, I removed the blower fuse, it stopped, I pull the ballast resistor and it also stops. Put all of them in and the fan is turning with the ignition turned off, key out etc.
Any ideas on what to check first?
Thanks
Rusty

[geofen8036]

Pull fuses from other circuits one at a time and see if you have carry over from another source. If you do. You may have short. Wires that may have worn into each other.

[Rtarh2o]

I found the problem, the ignition switch. I hooked up the battery, plugged the ballast resistor back in and the blower was very faintly running. Next I crawled under the dash and pulled the ignition switch and the blower stopped. To make sure I reinstalled the wiring to the ignition switch and removed each fuse one at a time, the blower continued to run no matter which fuse I pulled (except of course the blower fuse)
I will order a new ignition switch tomorrow in hopes this will solve the problem.
Rusty

[geofen8036]

A the joys of electrical trouble shooting. A short in the ignition switch. You may want to look over the wires going into the pin connector and the connector itself. Your on the right track. I used to be a SAABophile, the wires on some 1980s 900 models would melt in the center console area due to heat from the cat. This would cause curious issues. George

[Cocacolakidd]

A hidden fact is that with the key in the ignition the car is supposed to think there is someone in the cab. The Heater blower turns at 1/2 low speed to keep the condensation away while there is a warm body in the car/cab. A function of all 85.5 +, and may also be true for 83-85 early is to have air circulating at all times in the cab. This is a function when our cars are new always, but over time sometimes cars do not continue to do this because of bad/loose grounds and other worn parts.

[Rtarh2o]

I removed my ignition switch and ordered a new one. I opened up the old one to see if it was anything noticeable, upon inspection there were a lot of little broken plastic pieces inside the switch. Not sure if this was the problem but a possibility.
I considered trying to repair the switch but have tried things like this before without much success.
Hopefully the new switch will solve the problem, should know in the next day or two.
Rusty

[Rtarh2o]

Just got my new ignition switch installed, same problem, the fan runs at a very slow speed all the time, key in, key out etc.
What now? The fan speed switch? The ballast resistor? A short somewhere?
Where should I start?
Rusty

[Cocacolakidd]

The fan for the interior heat/ac will run at a low speed to keep the condensation down and air circulation going at all times. Normally one does not hear the fan but as they get older the fan can make more noise at times. The fan running all of the time is a normal function of our 944's, and is a factory standard.

[Rtarh2o]

The fan is supposed to run when the ignition is off? Key is out of the ignition? Won't this run the battery down?
Doesn't seem right.
Rusty