Air conditioning

[BuckeyeMan71]

I have a 2003 wagen that the compressor clutch won’t spin. Chilton manual shows I can jumper pins 1&2 on a 4 pin plug but mine is a 3 pin plug. Or is there a way I can do it with my VCDS? Thank you in advance.

 

[P2B]

The compressor clutch is a 2-pin connector. You can test the clutch coil with a multimeter, should read a few ohms. Open circuit clutch coils are not uncommon.

If you are referring to the 3-pin connector on the radiator, that's the temperature sensor for the fans. Both fans should run on low with key on AC on.

 

[Nuje]

The compressor also won't spin if there's no pressure in the system, and neither will the fans. But you can check the functionality of both as outlined by @P2B above.

 

[BuckeyeMan71]

I was referring to the pressure switch up by the firewall. It’s a 3 pin

 

[P2B]

I was referring to the pressure switch up by the firewall. It’s a 3 pin

It's not a switch, it's a sensor which outputs a signal proportional to system pressure. Jumpering the sensor would serve no useful purpose.

 

[oilhammer]

You should check out DanG144's thread, it will have some good troubleshooting for the HVAC/cooling system.

On a 2003, the fans should BOTH come on LOW speed if the A/C is switched on, even if the engine isn't running (so long as the key is on).

 

[compu_85]

It's not a switch, it's a sensor which outputs a signal proportional to system pressure. Jumpering the sensor would serve no useful purpose.

... it will actually blow the fuse for the fan control module I think.

 

[BuckeyeMan71]

I was referring to the 3 pin plug at the pressure switch.

 

[oilhammer]

As mentioned above, it is not a switch, it is a sensor. Don't mess with "jumping" anything, you'll run the risk of damaging something like the solid-state fan control module that controls the compressor and fans. This isn't 1985. And I'd trust a Chilton manual for a Volkswagen as much as I'd trust a BBQ invite from Jeffrey Dahmer.

 

[BuckeyeMan71]

You should check out DanG144's thread, it will have some good troubleshooting for the HVAC/cooling system.

On a 2003, the fans should BOTH come on LOW speed if the A/C is switched on, even if the engine isn't running (so long as the key is on).

Which one am I looking for? He has a lot of them. I tried just hooking a can up to it and it wouldn’t kick it on. I was also wondering how likely the pressure switch is to go bad. Also both fans do come on

 

[oilhammer]

Third time: not a switch. A sensor. And they never fail on the ALH cars. Typical 3-wire sensor: Power, Ground, Signal back to controller (in this case, the solid state Fan Control Module).

Here is Dan's thread:

Check your radiator/condenser fan operation NOW

Mk IV Manual AC electrical & cooling fan troubleshooting and repair Now is the time of the year to check that your pair of electric fans that provide cooling for both the radiator and air conditioner condensor are functioning. Do not needlessly age your Air Conditioning compressor by running it...

forums.tdiclub.com

Put the silly cans down. Please.

 

[P2B]

Have you checked fuses or clutch coil resistance yet? Those are by far the most likely culprits given the fans run.

 

[BuckeyeMan71]

Have you checked fuses or clutch coil resistance yet? Those are by far the most likely culprits given the fans run.

I’ve checked all my fuses but have not checked clutch resistance yet as I haven’t been able to get it up under it to do so.