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Discussion Starter · #1 ·
Hello Everyone,

Since we got our 00' NB This forum has helped more than you can imagine.:)

2000 VW Newbeetle 2.0 5-speed
103k (purchased with 60k)

Wonderful A/C.....
Clutch is not engaging....and its summertime

I am intermediate at my garage skills, never taken a car into get worked on, so usually I can hold my own.

I have replaced since owning the car in Oct 14'
-Timing Belt
-Water pump (metal turbine, not another plastic one)
-Coolant temp sensor
-Ignition control mod
-Spark plugs
-Spark plug wires
-Rear brakes(pads-rotors)
-Thermostat
-Accessory belt

A/C problem so far I have:
-seen that the clutch is not engaging
-Checked the fuses on top of battery
-BOTH fans DO operate the moment I turn on the a/c and fan
-Tried to add Freon (cheap kit), but did not as the gauge showed pressure in the red.
-Bought a cheap electric meter to start to check out the components.

I've read a ton of topics on this same situation, most are slightly different to what I need.... Any advice???

My thought is:
-Either dead FCM
or
-Compressor is toast.

The a/c operated until about 10k ago, and since it was cold out I didnt bother as we moved across country and had bigger things to deal with.

I remember before it went out, a few times turning it on while driving slow....it wouldn't engage, so I sped up or gave it a bit more gas and then it started fine. I remember a few times it was making loud squeaking(squeaky belt?) noises.

For me to check the a/c clutch, is there a proper technique? I did read about the jumper wire direct to battery. SO I would unplug the connector on the back of the compressor, then shove the wire into (one of the two sides...which one?) then to positive on the battery while having a safety fuse in place of course.

Would any other part be potentially bad since I had those systems before it went out? SO in brief:

-A/C clutch not engaging
-BOTH fans DO operate normally
-I cannot add freon as the system shows the gauge in RED zone (on cheap meter)
-Was making noise, being difficult before a/c would operate normally a few months ago.

Thank you all in advance! :D
 

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A/C clutch

There are a number of reasons an A/C clutch will not engage. Over pressure, under pressure, ambient temperature switch, coolant temperature too high, bad FCM, Bad fusebox,......

On the 2.0 I believe the blue or green wire is the ground.
and the red or brown wire is the positive. One way to really confirm that is to remove the plug and measure with an Ohm meter continuity from the car's chassis ground to each one of those wires in the plug while it's removed. one of those wires will be shorted to ground, that's the wire you put the batteries negative to test the clutch.
 

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Discussion Starter · #3 ·
Minor update,

We've been so busy we have just been dealing with no ac...but the temps and going to be upper 90's soon and it's no longer funny.

I've replaced the small 30 fuse on top of the battery (it was fine, just as a quick check changed it). Nothing happened.

I checked fuse 16 on the interior panel and it reads 12V.

Unplugged the connector at the AC Comp/clutch and I get no reading at all. I'll triple check right now.

Next step is supposed to be manually supply power to the ac comp clutch to see if it will engage.... Maybe I'm retarded but how can you put your hands down near the fans while it's running and blindly put a live wire inside the connector (impossible to visually see inside the female end of the connector.

Then also after that I'll begin checking the FCM which I suspect to be the cause since it may not be allowing power to get to the AC comp clutch.
 

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Discussion Starter · #4 ·
I did look again and saw a screw holding down the connector on the ac compressor, I'll remove that then if I can get the connector turned I can see inside and try to connect power to check the ac clutch.

Does it matter which of the two receives the power? Should the second wife/ground be connected to the battery ground or to the body?

I'll be using a wire with an in-line 30amp fuse and a second ground wire.
 

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posting

sometimes it's good to go read the previous postings that other folks reply, you might learn the answer was right there all the time. good luck man. :peekaboo:
 

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Discussion Starter · #6 ·
sometimes it's good to go read the previous postings that other folks reply, you might learn the answer was right there all the time. good luck man.

Thanks :). You know how it goes, sometimes your just exhausted or frustrated and over look things.

I just replaced the FCM with an OEM stribel one. The compressor/clutch is not engaging, there is power now to the ac comp/clutch...before it would have a slight surge and 0 volts. Now 12 :)

When you jump the ac clutch, what do you use to clamp the 2 prongs on the female connector attached to the ac comp? You've mentioned which wires, I've read lots of people doing it, I have thin hands but have one heck of a time.

If I've got to replace the whole compressor I will...I'm just afraid to throw parts at the car... I am like a lost puppy when it comes to electronics... Oh boy. One step at a time.
 

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12v

you have 12 volts at the compressor now but the compressor's clutch still does not come on? I would measure the plug on the compressor while it's disconnected and you should measure the clutch's coil resistance at around 8-10 ohms I believe if you don't measure that then it's a bad coil. BTW I used little alligator clips it's just a BITA to work on these cars. I avoid working on mine during the summer heat, too hot man. My first guess is it's open coil because if it was shorted coil you would be blowing fuses like crazy. LOL
 

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Discussion Starter · #8 ·
you have 12 volts at the compressor now but the compressor's clutch still does not come on? I would measure the plug on the compressor while it's disconnected and you should measure the clutch's coil resistance at around 8-10 ohms I believe if you don't measure that then it's a bad coil. BTW I used little alligator clips it's just a BITA to work on these cars. I avoid working on mine during the summer heat, too hot man. My first guess is it's open coil because if it was shorted coil you would be blowing fuses like crazy. LOL
Thanks for the tip!

I actually am about to test the clutch (literally just got alligator clips). My gut is telling me the FCM messed up and it also took out the coil...since the FCM was delivering 0 power to the ac clip (now it's 12v with new FCM). Here is to testing... Will post results.
 

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fcm

I don't believe the fcm can damage the coil it's sole purpose is to provide the 12vdc to engage the coil. Correction from yesterday when I said(8-10 ohms) the coil resistance can be as low as 3 ohms. good luck
 

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Discussion Starter · #10 ·
Thanks!

It was quite difficult to access since the Phillips screw holding the ac clutch connector to the compressor is stripped. But I did manage to clip them on, tried applying power .... Nothing.

Tried measuring resistance.... 0.

So it seems the clutch coil is no Bueno... I'll read up and see what other testing I can do (my multi meter cannot ready duty cycle).
 

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clutch

Thanks!

It was quite difficult to access since the Phillips screw holding the ac clutch connector to the compressor is stripped. But I did manage to clip them on, tried applying power .... Nothing.

Tried measuring resistance.... 0.

So it seems the clutch coil is no Bueno... I'll read up and see what other testing I can do (my multi meter cannot ready duty cycle).
Sounds like you found the problem and it being on a 16 yr old car I'm not surprised. It might be time to replace the compressor, dryer, and expansion valve. Make sure you replace the O-ring on every line you disconnect.
 
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