AC help- DAN G ?? 2003 jetta tdi

First- thanks Dan for that great AC trouble shooting guide but I have an issue that departs from the guide I'm hoping for some help .

First probelm- no AC Clutch engagement, 2nd problem - only one fan comes on when AC button engages.

What I found- Power to the AC clutch is bad and intermittent. I have seen 0 volts at the connector and I've seem 9.85v at the connector... never 12V. I found the clutch magnet is bad (open circuit) so I have a new one coming. I tried replacing the fan controller module- no change in behavior.

To be through, I followed the "no power at the clutch connector- 2B section). All fuses test good (verified power at both sides). BUT when I look for power at pins 5 & 8- I only have power on pin 8... nothing on pin 5. When I go to pin 2 on the high pressure switch, the wire color doesn't match the guide says not red blue? I believe the switch is working because when I unhook it, the single fan stops spinning but I'm not able to get 12v wen back probing the connector with it hooked up.

My wire diagram is from a 2004 and your guide was written for a 1999 ( i believe??) thoughts?

"When I go to pin 2 on the high pressure switch, the wire color doesn't match the guide says not red blue"

My diagram indicates blue/black, blue wire with a black stripe on pin 3.
Pin 2 should be a white wire going to the CCM.

Pin 1 is a brown/black wire merging with the compressor clutch ground and grounding at the front left side somewhere.

I -think- I've read the clutch does not get full 12V from the CCM but others may have to correct me.
Was there anything in the AC trouble shooting guide about this?

Wonneber-

thanks! I printed out the AC troubleshooting guide so i was going just by it as I don't have the 2003 diagram here.

Yea- on Dans guide it refers to pin 2 on the pressure switch being red/blue but that could be since the guide was written for a 1999...

but I still think I have a few problems going 1) I don't have 12V at BOTH T10/p8 & T10/p5... I only have it at P8?... the guide doesn't contemplate power on just 1 of the pins, it branches off based on wether both have or don't have 12v. I'm not sure if this could be a 1999/2003 difference? 2) One of my fans doesn't tun on with the AC switch..could be ralated to p5 not having 12V? 3) AC clutch power appears intermittent and never actually gets 12v... perhaps the 9.8v is normal? I didn't see anything in the guide about that?

Could be differences between the 99 and 03.
You list having a 03, same as mine.

Both fans red wires (red/white low and solid red high speed) are connected together going to the CCM and radiator coolant switch.
If 1 fan comes on with the AC on then the other sounds like fan motor is bad.

Both fans have separate ground wires going to the left front of the engine compartment.
I don't know if the CCM can tell if the one fan is not working but I don't think so.

I suspect you need to replace the clutch coil before continuing.

I found this on mine last summer. After replacing the clutch for non engagement. It’s the connector mounted on top of the starter. Right down alongside thee battery.



Wire #4 & #3 both provide juice to the compressor. Well I assume one is a ground.

Thanks Gents-

I just realized I've been using an outdated troubleshooting guide... I found Dans revised version but haven't had a chance to dive into it BUT upon quick glance, it appears I do only need 12 volts on pin 8 of T10, which I have.

It also stated the 9.8V at the compressor clutch is normal so next step- order a new clutch magnet and install.

BTW- I found no broken wires on mine (yet).

At this point, I've ordered a new clutch magnet since mine is definitely no good (open circuit). I suspect with what I've found so far, this will enable the compressor to run and then I'll just need to chase down why only 1 electric fan is working.

jav said:

I'll just need to chase down why only 1 electric fan is working.

Click to expand...

...because the other one is broken?


Go ahead and order a replacement.

Before ordering a new fan I would measure that 12V is getting to the fax that's not working.

While both fans are wired parallel to each other that doesn't rule out a broken wire.