Author Topic: Coolant fans + air conditioning  (Read 449 times)

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Coolant fans + air conditioning
« on: May 08, 19, 15:25 »
2003 tdi ALH jetta wagon

Noticed that the fans don't come on when doing the fan test, press AC button (turns on) and turn on low setting blower. Both fans should turn on right, they don't.
*Checked the left 30amp fuse on top battery is good
*Check fuse box
*Even replaced the fan control module under the battery

The fans still don't turn on. When I use the ac the compressor clutch engages and I do get ac through the vents and the blowers all work.

Is there something wrong with the fans itself or something wrong with something in the ac system. Maybe the pressure switch? Or could I be using two dud FCM as they do tend to fail a lot.

Not entirely sure if the fans even go on while driving as the temp usually sits even at 90 and never passed that. I beleive the tdi don't tend to over heat while driving. Recently replaced coolant sensor, thermostate, timing belt and water pump.

In stumped. I was stoked to finally have a vw with ac but maybe i won't be using it after all. Should I try to get it recharged first? Previous owners were older couple and maybe didn't check it. Any suggestions

« Last Edit: May 08, 19, 16:33 by snotrag »
94 Jetta gl vr6 -RIP / 92 Jetta 8v -RIP /
03 Jetta wagon tdi


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Re: Coolant fans + air conditioning
« Reply #1 on: May 08, 19, 18:40 »
So the fans don't come on at all? Jump the 3-pin switch connector in the left side of the rad. Pin 2 is the common 12v. Pin 1 is low speed, pin 3 is high speed. If the fans runs like this, then you have a FCM issue. If they don't run, you most likely have dead fans.

You checked the fuse on top of the battery, which is for the fan motors themselves. Did you check both of the fan fuses in the battery box? Third from the left of the large fuses, and first on the left of the smaller fuses. Have you checked the fusebox in the left side of the dash?
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