2004 Jetta TDI AC Inop

Hey guys, I've been pulling my hair out trying to diagnose why the AC in my car is extremely intermittent in working.

The AC will kick on at first start/ cold start and run for about 2 minutes and will quit. Many times I can get the AC to come back while on the freeway after the car has gotten up to temp and the fans are on to regulate temps.

I got the car in need of repair in many ways, and so it's got new cooling fans, a new FCM, and since I've got a Euro hook up local, a new compressor & condenser.

When I am looking at VCDS I get a 016 value for the compressor shut off time while the car is running and AC is "selected" but not working.


System is properly charged with 750g. I am at a bit of a loss with the situation because I feel I've exhausted my options, so any input would be great!

Thanks
Nick

Welcome to the forum.

Please post an Auto-Scan for context.

-Uwe-

I bet the ECU control relay for the compressor is overheating and kaput, very common due to poor size wiring used from bad insufficient grounds to AC clutch or shorted magnetic clutch winding from bad bearing.

Post an auto-scan for more complete attributes.

So sorry I have taken so long to reply to this; I brought a buddy in with a fresh mind on the matter and with his help we found out the new FCM had failed due to one of the bolts puncturing the plastic housing and shorting the FCM out intermittently.

Kind of feel like an idiot for following the "but it's a new part, it can't be faulty" logic, but after about an hour or so of diagnostic with someone who hasn't pulled their hair out the issue came out to be an intermittent short in the FCM.

Replaced the FCM, the bolts aren't puncturing the case, and all is well in the world again.