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Discussion Starter #1
I'm getting very close to having this '97 VR6 on the road. Been slowly chipping away at fixing all the minor/major issues that it had when I bought the car in February. I am now basically working on cosmetic stuff and making the car (hopefully) enjoyable to drive. However, I've recently discovered that the cooling fan seems to have a mind of it's own. Don't think it's an issue with the relay since it's working. What I am looking for some input on is why the fan would come on almost immediately after starting the engine? Temp is nowhere near the point where the fan should be on, but once it comes on, it doesn't shut off until I turn the ignition off. Can anyone help me out with some possible reasons and/or solutions to remedy this issue? I am not very familiar with VW's yet, but I understand how the cooling fan should operate, and when. It's definitely not right and I'd like to get it right before starting to drive the car. Thanks in advance for any input!
 

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Or the defrost on? AC compressor runs when air conditioner is turned on and when defrost is on. The subsequent refrigerant pressure is sensed and at a certain pressure the electric fan engages to lower the pressure and cool the compressed refrigerant. Try making sure the compressor is off before you start the car and observe the electric fan again.
 

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I'm certain the A/C is not on, nor is defrost. I have the temp setting right in the middle, ac button not depressed and condenser is not on with engine running. Zone control set on "floor" setting. I started the engine (and drove for a mile or two) today a few different times. Cooling fan turned on about 20 seconds after starting the engine one time, about 90 seconds after starting another time. It's quite strange to me what could be causing this. At first I was wondering about the cooling system having air in the lines after the heater core replacement done very recently. I've ran the engine for far too long now, left the cover of the reservoir off to burp any air bubbles and the coolant level is holding steady at normal level. To be honest, I'm not even sure if there is any refrigerant in the a/c system, or if that could potentially cause these symptoms with the fan? I appreciate the replies very much! I'll absolutely check again tomorrow about the a/c, but having just had the entire dash/interior out of this car to get at that heater core and checking everything after reinstallation, I'm certain the a/c is not turned on currently.
 

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About ~13 yrs ago, I owned a 95 Passat VR6 that had a similar issue. The cooling fan control module was faulty.

This module, on the 95 VR6, was on the lower driver's side frame rail. To locate module, follow the wiring harness from the fan back to the module. Of the two plugs on the module, you want to unplug and test the "signal" plug with 8 wires. If you can unplug this one, test each wire's voltage compared to ground with the ignition on.

More than likely, it is the fan control module, but you must locate a copy of the electrical schematics to "prove" that the proper "signals" from the car's electrical system are telling the (supposedly faulty) module when the fan should run.

Here's a link to the schematic for a '93 Passat VR6. It may not be identical to what you have, but the module is the same and likely the wires in your "signal" harness plug are the same colors as shown in the schematic.

Good Luck
 

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Sincerest thanks and appreciation for the info E-man! Apologies for the delay in responding to your post, just now saw it. Haven't been on here in a while as it seems there aren't many who actually respond to questions, so again, thank you. I'll look into that for sure. I've got the battery back out right now and I know exactly where the module you mentioned is. I'm confident it's very similar between the years you mentioned so I'll give that a look. There's definitely something wrong. Fan kicks on before temp gets to 160 and stays on until I shut the engine back off after that. I had the fan turn on at 160 again today, then it momentarily shut back off, then kicked back on again. Strange deal, I hope your insight helps get that taken care of!
 
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