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View Full Version : Heat & A/C Ok, Think I fixed the AC


Silverbullet
07-14-2013, 08:28 PM
My AC worked great... for about 15 minutes of driving... then the cabin would get warm... Every time I go out, it worked great, then... not. When I got home I looked and the AC Clutch was not pulled in. I checked for Power to the compressor, and it had power. I ran a jumper from the + post to the compressor, and it still did not pull in... then I Bumped the front and it pulled in...

So I was thinking when it got hot it was not able to pull in... So I looked up the air gap and it is to be .016 to .031, and mine was .052, way too big. So I pulled the Clutch off, removed a Shim and it was .028, and put it back together, and now the air gap is .024 and so far, it is working great, turns on and off, even when hot.

http://i116.photobucket.com/albums/o19/AtHomeSoda/ACClucthRemoved2_zpsda41f1bc.jpg (http://s116.photobucket.com/user/AtHomeSoda/media/ACClucthRemoved2_zpsda41f1bc.jpg.html)

http://i116.photobucket.com/albums/o19/AtHomeSoda/ACClutch_zps5b6d049f.jpg (http://s116.photobucket.com/user/AtHomeSoda/media/ACClutch_zps5b6d049f.jpg.html)

http://i116.photobucket.com/albums/o19/AtHomeSoda/ACWrench_zps63032cd6.jpg (http://s116.photobucket.com/user/AtHomeSoda/media/ACWrench_zps63032cd6.jpg.html)

A couple of tips, you need to drill the hole in the "Universal AC Wrench out bigger as you can't get the 19mm socket through it. To remove the shim, that is behind the key-way on the shaft, use a pick up tool maginet, works great. Check your gaps...

Craig
David T
07-14-2013, 09:42 PM
We have seen this problem on a few cars. It is not common but it isn't rare either. The symptom is you get cooling but when it shuts down to cycle it won't reengage. This HAS to be a problem from all the way back to when the car was built, there is no way the gap can change that much. Once fixed it should never happen again (at least on THAT car!).
David Teitelbaum
DMC5180
07-15-2013, 09:53 PM
I do find it rather ODD that .020" would make that much of a difference, especially when you see how much Flex is in the clutch end plate. I guess you learn something new every day. Could it be the electromagnet is just too weak to pull the plate?
Silverbullet
07-16-2013, 01:31 AM
Well it would pull in when it was cold, and when it got hot it would quit... spec is .016 to .031, so mine was .021 over that... Now at .024 it seems to work fine... I guess the spec's hold true...

Craig
Bitsyncmaster
07-16-2013, 07:23 AM
When the copper wire in the magnet gets hot, its resistance goes up. That equates to less current and therefor less magnetic power.
Silverbullet
07-17-2013, 01:32 AM
When the copper wire in the magnet gets hot, its resistance goes up. That equates to less current and therefor less magnetic power.

This seems to hold true... or it is a weak coil... but NOW it seems to work great... I went to DMCCA today, it was hot outside and it was cold inside, the whole trip, which was NICE. Good to see Danny again. Seems the WILL be moving to Huntington Beach in about a month or so...

Craig
Ron
07-17-2013, 04:01 PM
Slippage from lock-up (overcharged, restrictions, etc), or long term excessive cycling (undercharged, restrictions, electrical connections, etc) can cause the wear, especially to the cast iron piece(s). It's just a matter of how smooth it winds up from there, with the latter being more forgiving...

Note 20 thousandths sounds small, but considering the mean, it was ~double...

======================

For those reading in the future,

N:10:04 gives the following as a coil test:

3.6A to 4.2A at 12V.
Henrik
08-08-2013, 05:53 PM
We have seen this problem on a few cars. It is not common but it isn't rare either. The symptom is you get cooling but when it shuts down to cycle it won't reengage. This HAS to be a problem from all the way back to when the car was built, there is no way the gap can change that much. Once fixed it should never happen again (at least on THAT car!).
David Teitelbaum

Not sure what makes you say that. Clutch wear after years of cycling is very common and very typical.
DMCMW Dave
08-08-2013, 06:11 PM
Not sure what makes you say that. Clutch wear after years of cycling is very common and very typical.

Depends on where you live. Probably very common in Texas, but I've never seen anyone wear out a compressor in northern Illinois.
Silverbullet
08-08-2013, 06:41 PM
Well, the car only had 42,000 miles on it, 43,000 now (more fun to drive when AC Keeps working) It had 40,000 in 1993, and was moved from CA to TN and sat, till last year, I bought it and brought it back to CA and back to life. It is a fun car to drive...

Craig