Engine Fan and AC Fan

[ckev70]

2007 VW Rabbit:
Does both engine fan and AC fan turn on when AC is turned on or does engine need to reach operating temp?
Is there a way to test each fan directly with 12V...if so which pins?

Thanks

 

[GTI's]

With a proper scan tool, you can do an output test on the fans, and they will ramp up speed and then come back down, and also see if the fans have any trouble codes.

The smaller fan can be tested by disconnecting it from the harness from the larger fan and applying 12v power and ground to its connector plug. The larger fan that holds the fan control module Per Vw (not supposed to be tested by putting power & ground to the wiring for the fans motor it can cause damage) is not to be tested in the same fashion as the smaller fan but with a scan tool output test. With that said some have briefly put power & ground to the wires but it is opposite of how you usually would connect power & ground.

With the AC on both fans should come on if the temperature right. With a scan tool you can look at the fans specified/requested Vs actual and see what is going on. Fwiw the spec is usually at about 12% with the engine on and the fans not turning so do not let that fool you its normal.

 

[ckev70]

I dont have the proper functioning vcds unfortunately or the functional test would have been easy.

I warmed up the engine...the analog dash temp was showing just shy of 190 but no fans spinning. Increased throttle around 2500 rpm and saw gauge increase slightly above 190 still nothing. Ran it for a few more minutes and both fans turn on. AC seemed cool.

My nephew who drive this now said AC didnt get cool/cold for a long time. His dri es are short distance but lives in a hotter climate (thus needing/wanting AC).

From what i can interpret, both large and small fan are functional and the issue seems to be related to the ECU not issuing the command to turn on the fans (just black box guessing) which may be just how this gen VW ac system is designed.