RADIATOR FANS not spinning correctly + CHECK ENGINE LIGHT

[zoemayne]

I've been driving with a radiator fan problem for a few months now and I dont know if I should even try to fix it. It all started when I took my car to goodyear and they flushed the radiator and replaced the coolant with non-dexcool antifreeze. That caused (midas told me and I have to agree) a sensor to go out and the low coolant light to come on. I had absolutely no coolant leak. I assumed it was the radiator fan because one of them would not spin sometimes- and a fan would make clicking noises while they were coming to a stop(once I cut the car off). So I had the fans replaced - the whole assembly by a local mechanic for $200 total. So the mechanic noticed another problem the fans would not spin at high speed. So the mechanic hooked up the fans "direct" to spin high speed all the time. With the fans hooked up that way it causes engine light to stay on all the time. Also the "low coolant" light was still on. I drove it 1 day after getting it from the mechanic and it overheated!!! Took it to the same mechanic and he said that the fans were not spinning at all so he replaced a fuse now its working at high speed again. (This mechanic said that the fans were not spinning correctly because there is something wrong with the fuse box). OK the car is working but the engine light is on and the low coolant light was still on. So A friend told me to take the car to MIDAS. MIDAS were mighty honest they told me exactly why the low coolant light was on w/out even checking the car and replaced the sensor. They tried to clear the engine light but to no avail because the fans are constantly spinning high speed. With the fans spinning at high speed the car is running at about the lowest temperature(the temp needle is at about the lowest mark most of the time). I dont think that is good for the long run. The engine is not as cool as the temp gauge says but the radiator fluid is warm enough to where I can always pop off the radiator cap after a drive and stick my finger in it. So recently in FLorida the temp dropped so the car is running even cooler. On the night the coolness came I started the car up and sputtered off (the lights dimmed engine cut off and it was shaking while it ran). So I started it up and as long as I kept my foot on the gas It wouldnt cut off. In the morning I looked under the hood and noticed a loud noise (air burst) above the hood on the right side. It was a hose that was loose - I connected it and the car is running fine now. MIDAS told me that in order for them to correct the problem they would have to reverse what the other mechanic did and diagnose the fan speed issue. They said they had no idea how much it would cost me that I would have to just go along. I dont like writing blank checks so I didn't take the chance. MIDAS also said that they have never heard of a fuse box going out and that was not likely the issue. MIDAS also told me the fans would eventually burn out and that the car is burning more fuel at the low temps. I dont know what should I do!!!

OK a week ago I took it to a friends house to have powersteering leak fixed and check out the fan. He showed me how it was wired to a fuse and he made some change to it and now it is constantly spinning at the speed thats one below the highest speed. So that change got the engine light to cut off and the car is now running at normal temps. BUT now the fan is doing the same thing one of them are not spinning once I start the car-only one fan spins once the car is on. So after a drive the other fan cuts on I dont know if thats correct. Also I stuck my finger in the fan and gave it a little push - I started to spin. I did that a couple of times and it would spind once I push the fan a little. I know it is not the fan because I just had it replaced and the previous fan was doing the same thing. Is there a computer controling the fan speed? Has this ever happened to anyone here? zoe

[crazy Jim]

The first fan should come on when the engine coolant temp is around 220, the second fan should come on when the Airconditioning compressor is running.

[richtazz]

What year is your car? It makes a big difference as to how the fans are controlled.

[zoemayne]

its a 2000 and right now it has almost 85kmiles. its the base model. This has been going on since about 80 k miles.
This is how the fans spin once the ignition is in the Acc position fan1 is spinning. After running the car the 2nd fan cuts on. So the post does make sense. But I dont think the fan is supposed to spin as soon as I put it in the Acc position.

Also I'm gonna have to do other things on this as in the fuel pump, rotors, who knows. Also I hit a bump and the airbag light came on and now it is on most of the time. I may have to post a new post for that one too. And also the airconditioner works only at the two highest speeds 5 & 6.

Thankx for the replys crazy and rich

[adamgtx]

coolant temp sensor perhaps?

[GMMerlin]

The PCM controls the coolant fans thru 3 relays.
Low and high speeds are changed by powering the fans either in a series or parallel circuit.
When low speed fan is requested BOTH fans run at low speed, when High speed is requested, both fans run at high speed.
By wiring the fans directly, the pcm cannot monitor the fan operation and this is why the SES light is on.

[richtazz]

The blower issue and airbag light could both be due to a faulty ignition switch/harness assembly. The contacts get corroded/pitted and start to arc, causing all sorts of odd electrical gremlins, especially in the ignition controlled circuits. The other common issue in the blower fan problem is the blower resistor. They are a common failure part, and are located in the heater box near the blower motor. If you notice water intrusion in the heater box, install a cabin air filter to improve the seal.

On the fan issue, the PCM uses the signal from the CTS to determine proper fan speed. If the sensor is mucked up with sludge or not immersed in coolant due to an air pocket, it will cause the fans to act irradically.

[zoemayne]

i let some one take a look at it and he showed me how it was wired direct and he didnt make any changes (supposedly) ....after he looked at it the check engine light is gone and the fan is not always spinning on high speed. But the fan still automatically comes on once the ignition is in the on position. I think i'll leave it like this.