My radiator cooling fan isn't working, can't figure out!

Post by **shiloh51933** » 11 Mar 2011, 11:56

Okay here's the deal, I have replaced the temperature sensor, the cooling fan relay and drained/filled the engine cooling system. So I was thinking it was maybe the fan itself, so I was going to replaced but I came across the auxiliary fan unit and I'm thinking it could be this but again I'm not sure. The three things I've done already to this system were things I like to do when tuning up a used ride but now I'm thinking could it be this auxiliary fan unit. Would this cause the fan to not go on? How do I test it to see if it's good or not? thanks. I can't find this auxiliary fan unit, I was just told about it today but where is it??

Post by **Ozark Lee** » 11 Mar 2011, 18:13

It is actually normal for the fan to run very little unless you either have the air conditioner on or you are stuck in traffic in the middle of August.

You can test things by grounding, one at a time, the relay pins associated with the yellow and the yellow/white wires that go to the center of the cooling fan relay. One should turn the fan on high speed and the other should turn the fan on low speed.

If that works then the fan and the relay are good.

If you still suspect problems it is either the ECU or the wiring from the ECU to the relay.

...Lee

Post by **shiloh51933** » 12 Mar 2011, 05:58

Ozark Lee wrote:It is actually normal for the fan to run very little unless you either have the air conditioner on or you are stuck in traffic in the middle of August.

You can test things by grounding, one at a time, the relay pins associated with the yellow and the yellow/white wires that go to the center of the cooling fan relay. One should turn the fan on high speed and the other should turn the fan on low speed.

If that works then the fan and the relay are good.

If you still suspect problems it is either the ECU or the wiring from the ECU to the relay.

...Lee

So you don't think it could be the fan itself, I'll check the wiring from ecu to relay again.

Post by **Ozark Lee** » 12 Mar 2011, 07:12

So you don't think it could be the fan itself

It could be but the test at the relay will help you narrow it down. Normally when I do electrical troubleshooting I start at one end or the other but this is a very simple test that will tell you which half of the system has a problem and cut the testing time in half.

...Lee

Jedlacks · Post by **Jedlacks** » 12 Mar 2011, 11:10

Instead if starting a new thread, Shiloh and I have similar problems.

I grounded the yellow and the yellow and white and the fan came on. When the car is hot and I tap the relay the fan starts and stops immediately. Any thoughts on this being the ECU or the wiring from the ECU?

Post by **Ozark Lee** » 12 Mar 2011, 14:11

When the car is hot and I tap the relay the fan starts and stops immediately.

Check, and use some contact cleaner, on all of the connectors at the relay. I had a similar problem on my '94. Also inspect the wiring at the base of the connector as well since it is fairly exposed and subject to damage while other repairs are being made. Often the damage to a wire is not visible but moving a wire around will make the problem wire identify itself.

...Lee

Post by **shiloh51933** » 14 Mar 2011, 05:39

Yeah I replaced the relay and cleaned everything up on that side(connectors/wiring good), I haven't tried running power directly to the fan itself cause I've been real busy with other things.

Post by **jimmy57** » 14 Mar 2011, 08:55

I have not seen anything in this thread yet that states why anyone thinks their fan is not working right. What are the indications of problem?
Depending on how hard you tap the relay, the fan will start and immediately stop.
Does the gauge go up over 3/4 way?
Does the car get hot and radiator tank burp coolant out?

On cars using electric fans the radiator is sized up and fan will not come on for LONG periods of idling in cool weather. If it is around freezing it may be 30 minutes of idling out of gear for fan to run.
If it is below 65 and compressor is running the fan will still run infrequently and for short bursts.

Post by **shiloh51933** » 14 Mar 2011, 13:59

jimmy57 wrote:I have not seen anything in this thread yet that states why anyone thinks their fan is not working right. What are the indications of problem?
Depending on how hard you tap the relay, the fan will start and immediately stop.
Does the gauge go up over 3/4 way?
Does the car get hot and radiator tank burp coolant out?

On cars using electric fans the radiator is sized up and fan will not come on for LONG periods of idling in cool weather. If it is around freezing it may be 30 minutes of idling out of gear for fan to run.
If it is below 65 and compressor is running the fan will still run infrequently and for short bursts.

This fan has not gone on once since I got her over a year ago, the temp goes over the half way mark and will keep going if I don't turn heat on full blast. The relay is brand new, the temp sensor is brand new and when the and the engine does not maintain a constant level as it should, yes the thermostat is good. I didn't mention symptoms cause I know the fan won't go on but yes I definatly should for everybody, my bad. I also drained twice and filled with Volvo brand coolant/distilled water-50/50, all the hoses are good, expansion tank/cap are good, radiator is good

tomellis · Post by **tomellis** » 14 Mar 2011, 14:07

This may be a silly question, but have you run power straight from the battery to the fan to make sure the motor is good? I didn't see anywhere in your posts that you have done this. If you haven't done that yet, it is where you need to start.