Fan not coming on

[momo]

I am having the exact same problem. I went to the dealer, who said that the problem was the whole fan assembly, and was quoted the same $650-700 estimate. I went to the local garage, who told me that they were able to get the fan working at both speeds with a sensor tool (no idea), and that it was likely a computer problem. I went back to the dealer with this info, they plugged in their little box into the car, showed me that the high speed works, but not the low.

What I want to know is is that little dealer box that he plugged in enough of a test for me to believe that the fan is bad?

[TheAnt]

Originally Posted by momo

I am having the exact same problem. I went to the dealer, who said that the problem was the whole fan assembly, and was quoted the same $650-700 estimate. I went to the local garage, who told me that they were able to get the fan working at both speeds with a sensor tool (no idea), and that it was likely a computer problem. I went back to the dealer with this info, they plugged in their little box into the car, showed me that the high speed works, but not the low.

What I want to know is is that little dealer box that he plugged in enough of a test for me to believe that the fan is bad?

Except for things I have heard recently I would expect ANYBODY to check both relays before using just a code reader to say the motor is bad.

As far as the who;e fan assembly, if the frame and blade are OK all you need is the motor. $119 or near that at O'Really and Auto (shudder) zone.

Back to the main story if you read all my posts I found a corroded female (wiring harness side) connector. I cleaned it the best I could but the problem came back.

You can have bad windings in motor or bad brushes in the motor. Some folks can fix those but I'd just as soon get a new motor.

OK, continuing to work out from inside the motor you could have bad wires to the connector, bad connection at the connector, bad wires to the relay, bad relay(s) bad signal from the computer, bad computer, bad sensor.

The right way to find out is to read the voltage as close to the motor as possible under the conditions that make it run. There are temperature thresholds and the air conditioner being on (I think max) will make it come on regardless of block/water temperature.

You can pull the tops off the relays and watch them click in if you want but don't expect that just because the relay engages that it makes good contact. The points of contact can get burned/oxidized and they get worse because of heat causing more oxidation.

Anyhow, check connections first because they are cheap to fix.
One of the relays (I think the low speed) can be swapped with another. I chose the horn relay because I could easily test it and do without it until I get another.

One more thing. You can disconnect the fan at the connector Crewzin posted and connect tthe middle fan contact post to ground. Then connect each of the other wires to +12v. One will be the high speed and one will be the low speed. Look for a strong start and spin up to speed. A weak start may indicate bad windings, brushes, or bad connection possibly even in the motor housing.

anyway that's my $.02 Alot of verbage for 2 cents, eh?

[momo]

Wow, thanks. The guy at my garage said he would re-check the fan tomorrow. I will print out your e-mail and have him check all of those things. I bought a new relay for $6 to see if that was the problem, but the search continues. I will check on getting a new fan motor. You guys are great. I'll post what I find.

[nutcase]

Originally Posted by TheAnt

Except for things I have heard recently I would expect ANYBODY to check both relays before using just a code reader to say the motor is bad.

As far as the who;e fan assembly, if the frame and blade are OK all you need is the motor. $119 or near that at O'Really and Auto (shudder) zone.

Back to the main story if you read all my posts I found a corroded female (wiring harness side) connector. I cleaned it the best I could but the problem came back.

You can have bad windings in motor or bad brushes in the motor. Some folks can fix those but I'd just as soon get a new motor.

OK, continuing to work out from inside the motor you could have bad wires to the connector, bad connection at the connector, bad wires to the relay, bad relay(s) bad signal from the computer, bad computer, bad sensor.

The right way to find out is to read the voltage as close to the motor as possible under the conditions that make it run. There are temperature thresholds and the air conditioner being on (I think max) will make it come on regardless of block/water temperature.

You can pull the tops off the relays and watch them click in if you want but don't expect that just because the relay engages that it makes good contact. The points of contact can get burned/oxidized and they get worse because of heat causing more oxidation.

Anyhow, check connections first because they are cheap to fix.
One of the relays (I think the low speed) can be swapped with another. I chose the horn relay because I could easily test it and do without it until I get another.

One more thing. You can disconnect the fan at the connector Crewzin posted and connect tthe middle fan contact post to ground. Then connect each of the other wires to +12v. One will be the high speed and one will be the low speed. Look for a strong start and spin up to speed. A weak start may indicate bad windings, brushes, or bad connection possibly even in the motor housing.

anyway that's my $.02 Alot of verbage for 2 cents, eh?

It is the High speed relay that can be swapped with another relay---the horn relay. There is not another relay that can be swapped with the low speed. Just check the posts by crewzin.

[TheAnt]

Originally Posted by nutcase

It is the High speed relay that can be swapped with another relay---the horn relay. There is not another relay that can be swapped with the low speed. Just check the posts by crewzin.

Sorry to reply ti such an old post but I want to thank you if I got the relays mixed up!.

What also brings this to my attention is that I still have problems, possibly a bad head/gasket, whatever...

Back to the relay, a tip for troubleshooting from an old electronics troubleshooter:

I pulled the top off the High speed relay (I think without the engine running but odds are the ig switch was on) ann pressed the top/swing arm toward the magnet and it was a noisy connection. By that, I mean it arced a good deal as I closed it and I had to press fairly hard to get the fan to kick on but it did. If you try this be sure not to apply pressure on the flexible/copper leaf between the hard magnet and the contact itself. If you bend it, you risk affecting its performance anyway. Press only on the thick metal directly opposite the magnet.

My impression of the connection the based on the flexibility of the center contact strength vs. how hard I had to press to make contact was more than the magnet would do. I expect that meant a burnt contact. The replacement at O'Really was around $10 so no great pain there.