1995 Jetta III GL - Radiator fans only working when AC is on

Hello ...

My daughter came back from work and said the fans on her car weren't working and it was running hotting than normal (gotta love a kid that checks that stuff out!).

I pulled the fuse in the fuse box and it is fine. I am able to get the fans to run when the AC is running, but not without. I'm thinking it could be the relay but I have no idea where it is or which one it is.

Can anybody lend a hand with this?

Thanks!

Jeff

Reply to
tombstone
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I would check the: radiator fan switch and the radiator fan module almost under coolant bottle

Reply to
dave AKA vwdoc1

I'm assuming the radiator fan switch is mounted in the radiator. If I disconnect it and just the wires would that trip the fan? Is there a test for the radiator fan module?

Thanks again guys!

Reply to
tombstone

most later model and A/C equipped cars have two speed fans so there are three connections on the fan switch. but yes, if you can jump it out and make the fans run then you know that the thermoswitch is the problem. and it usually is

nate

Reply to
Nate Nagel

Is this the part I'd be needing to replace?

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Where is this located on the radiator? On my old BMW is was on the passenger side bottom. I don't recall how messy the process was. Will I lose all the antifreeze?

Thanks again guys!

Jeff

Reply to
tombstone

Yes that looks like your rad fan switch! TEST THE WIRING FIRST at the rad fan switch!!!!! Like Nate said. Fan comes on at both speeds by jumping different terminals at the wiring plug............YES then Change rad fan switch when the coolant is cold and the cap on the expansion bottle. Remove and install that cap to remove any possible pressure in the cooling system. I think you can access the rad fan switch from the top so it should not be too messy a job. Prepare to install the new one just before getting the old one out of the radiator. Wear some latex or nitrile gloves and safety glasses for the eyes and be quick with the switch! [8]^)

Get power and ground to the fan to test it directly..........if it comes on then it might be time to test the radiator fan module. There will probably be two wiring plugs going to that and you should notice 2-3 fat probably red wires. Test for power at all wires, ign can be off! Post results! I will have to remember how I have tested them before without just swapping in a known good one from the junkyard.

Reply to
dave AKA vwdoc1

I tested the wiring at the rad switch and got the desired results. I had power (key or no key) and was able to get the fans running by jumping the hot wire to each of the other two. I also checked for power at the relay (although I'm assuming I didn't have to).

Replaced the switch and voila - at 195 degrees the fans turn on and run for a period of time after shutting down.

There was only one fuse located in the relay. Should there be another one and what would it protect?

Thanks again guys!

No onto the tranny problem.

Reply to
tombstone

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