A/C problems 2002 New Beetle 2.0

[pkhanc]

I am having problems with my A/C. When the A/C works, it works great. However, it just quits working frequently, (usually when it is 95 degrees outside). I have had the freon checked by VW dealer as I suspected either a low or high pressure switch was the problem. They said everything checks out, (of course the A/C was working when I stopped by). I just installed a new fan control module which is a pain to install as the battery box had to come completely out. Did not help as the problem still exists. I have checked the fuses and wiring on top of the battery and everything checks out ok with my meter. Any ideas from anyone???

[pencilneck]

The most common AC issues I've seen (in random order here):

Low charge due to [xxx]. Your system holds like 750 grams of charge. One of the first things I do when checking an AC system is to pull the charge out and see how much it had, pull vacuum to see that is holds vacuum then recharge the system. This gives me a chance to sit around and drink soda as well.

Pressure Sensor: There is a pressure sensor just before the expansion valve at the bulk head. The sensor just unscrews so it only takes a few seconds to swap them out with a known good sensor.

Bad Fuse Block: Somewhat common problem with the NB, the fuse block on top of the battery, the fist of the three 30A fuses, take a close look and see if there is any heat damage to the fuse block there. The fuse will be good, but a poor electrical contact between one of the fuse blades and the fuse block itself will generate a lot of heat... melting plastic and burn a hole in the plastic flap cover kind of heat. Said fuse goes to fan control module... fan control module is what allows AC clutch power up. I check every NB fuse block I come across since it is a somewhat common issue.

Outside air temp sensor: At the base of the windshield, on the right side I think, is a temp sensor, two wire. Some of them rattle if you shake them, normal. Sometimes if the AC isn't working you can tap on them with a screw driver handle and the AC will kick right on. Or swap your out with a friends car and see if he ends up with the same problem (do this with the pressure switch as well... but only do one at a time).

That relay under the dash: I'm to lazy right now to look at the wiring diagram, but there is a relay under the dash for the AC. I've seen where said relay will get a crack at one of the soldier joints that results in a non-working AC. Check your wiring diagram and locate said relay, pull it out, pop the cover off and carefully inspect the soldier points for the terminals. If you find one crack, just reheat that soldier joint.

Wife turning off AC when I'm not looking: The price you pay when you say "I do". No know repairs for this issue.

Screwy Fan Control Modules: I have a known good one on hand that I just plug up to see if that is a quick fix. Now you have a test module as well.

I hope this helps out. Ignore my typos (easter eggs).

Later.

[pkhanc]

Thanks for the tips! I'll advise if any of them fix the problem.

[JJM#RD]

I just went through the AC (no ac) that is recently. I went to three different places. First place suspected module, but did not have it, second place suspected module and replaced but it did not fix the problem. Third place found problem to be the fuse block on top of the battery. so sounds like another vw has the same problem. My ve iis 2002 with 56k m iles. I love the little vw, glad to have it back. Fun to drive. Although it is a rough rideer. Wonder if all vw's beetles ride rough? It is like i dont have any shocks.

[vdubbugman53]

hell yea my car hater RR track even b4 i lowered it. feels like the suspension bottoms out alot even when my other cars dont

[hako]

With all these electrical gremlins I'd skin this cat a different way - simply run a fused ignition +12v cable to the compressor electromagnet clutch and the cooling fans via the low pressure switch. Switch the +12V via a relay which self latches when you press a button on the dash. This way the main electrical load is removed from the equation and you have full control over the aircon (as long as the cabin fan works). Hasn't happened to us yet but if/when it does we'll make it simpler than the factory design.
This will not give "climate control" but here in North Queensland when you need cooling you need the compressor running full time - and thats for 9 months of the year.

[dnosille]

My system was working fine and i took it in to have the inspection done, and when i picked it up I have a strong oil smell coming from my vents befor i even cranked it up a coupe of days later when i turned on the ac it didn't cool. return to dealer they said the high and low pressure sides of the a/c were 70 psi, holding pressure but not cooling. they recomended complete a/c replacement, help!: