AC clutch

[nelson20]

Hi all,

When I got my 89 SEi the AC didn't work. Did the LPS test and the compressor kicked in so I figured it was low on R-12. I took it in to have vacuumed, tested for leaks and refilled. The mechanic had it on a vacuum for 5+ minutes without any drop in pressure. He put dyed R-12 in it and ran if for 5+ minutes and couldn't find any leaks. So that baffles me as to how the freon was gone (maybe it was taken apart?).

So the AC worked great for a week, then stopped. A couple days later, it turned on for 15 seconds and then stopped again. It's done that a couple more times since then. So this time I did the LPS test again and it wouldn't kick on (telling me I still have good pressure?). I connected the LPS to ground and my fans turned on and I could see that the clutch 'wanted' to kick in (it was clicking and kinda jerked a fraction of an inch) but wouldn't ever completely turn on.

While the AC did work my idle was awful with the AC on - hovering around 500rpm. Judging from the pictures I've seen on here it looks to be the unfavorable Keihin.

Just wondering if my clutch is toast or getting toasted? Does R-12 units use oil? Do most mechanics put oil in after vacuuming an AC unit? Could a lack of oil cause my clutch to not kick in? Can a Keihin compressor clutch be rebuilt? Anything else that could cause the clutch to 'almost' engage? The belts turn fine btw.

I appreciate any feedback. Thanks!

[AccordB20A]

i dunno how it works but when i was using my aircon compressor for an air compressor for my air horn it decided to seize due to lack of lubricant. maybe yours did the same and burnt its clutch out

[Dr_Snooz]

Five minutes of vacuum would only tell you if you have a massive leak in the system. In fact, five minutes wouldn't even be enough to remove moisture from the system, which you have to do if you don't want problems down the road.

Chances are a lot better that you have a slow leak. You want that system to hold vacuum for at least an hour, and ideally, overnight.

I don't think you have a clutch problem because the system was working "great" for that week.

You have a can of UV leak detector in there now, so all you have to do is look for the bright neon yellow stain. Use a good, strong UV light and not those cheese-eatin' pen lights from Autozone. They're not very good.

[nelson20]

If I had a leak though, wouldn't jumping the low pressure switch cause the clutch to engage - if the clutch was good?

[nfs480]

The clutch relay could also be bad.

[nelson20]

Sorry, I forgot to mention that I replaced the Clutch Relay.

[Dr_Snooz]

If I had a leak though, wouldn't jumping the low pressure switch cause the clutch to engage - if the clutch was good?

If you want to check the clutch, remove the belt and check the pulley for play and smooth operation. If it's sloppy, replace the clutch. Then unplug the electrical connector and check the resistance between the connector terminals on the clutch. It should be ~3 ohms plus/minus 0.3 ohms @ 68°F. Finally, measure the pulley to pressure plate clearance with a feeler gauge. It should be between 0.012 & 0.024 in. See the manual for a diagram of how to do this. The manual is available below for download:

http://www.pauldesign.ru/honda/shopmanual.html

The fact that it was running great before makes we think that your clutch is okay. Most of the time, these systems fail by springing leaks. My Keihin sprang leaks. You should definitely check for them, especially if leak detector is already in the system. All you have to do is poke your head under the hood and look around with a good black light.

At this point, I'd say you shouldn't put too much time into that Keihin. With R-12 at the price it is currently, it will cost you $200-$300 to fill it. If history is any guide, it will reward you shortly after by leaking it all out again. You won't have to do this many times before you've exceeded the cost of buying a Nippondenso compressor and converting to R-134. I'm not sure how long you plan to keep the car, but that's your best long-term solution. Some guys here have used R-12 alternatives (Freeze 12, ES-12, etc.) with success. That might be a good short term solution, but I haven't tried it.

[nfs480]

One other suggestion, I know you've replaced the clutch relay but did you replace it with a keihin relay (if it's a keihin) or a nippon denso relay. Because I think there is a difference between the two relays.

[nelson20]

I looked last night with a black light and didn't see any leaks that I could tell. What color would the dye be?

I also didn't know there were two different relays. I just grabbed one from Schucks.
So if this isn't caused by a leak, is it worth fixing a Keihin clutch?

[nfs480]

Fixing the clutch is a lot cheaper than replacing the system with denso component and i've had a keihin running with r134a for over a year now with no problems. I would say it's worth it to fix the clutch but that's just me.

[nelson20]

Anyone on here ever work on a Keihin clutch? The shop manual shows a step by step but it doesn't say if its for the Nippon or Keihin. Clutch keeps working randomly, yesterday it worked great for an hour of some running around. Today it doesn't. Seems if it was seized it wouldn't work at all?

[Oldblueaccord]

Well that does tell you that the compressor is not shot. But removing and replacing the clutch may be hard on the car I would think you will need to impact it off. Usually the rubber ring goes bad.


wp

[nelson20]

Ok, so one more hint to this problem. I suck at electrical stuff so I don't know what this means... the clutch kicks on when the car has been sitting but running. When the cooling fans kick on, then the clutch will kick on. When the cooling fans stop, the clutch stops. Any ideas?

[Oldblueaccord]

Well then it might be something faulty with the AC switch in the dash. When that switch is on the fans are on.

Not sure if theres a relay related to the switch or not but look and see if the AC button light goes on and off it should not.


wp

[nelson20]

The AC button's light does not go off when the AC is on. Can anyone put that Air Conditioning electrical schematic thats in the shop manual in laymen's terms? That is, of course, if it sounds like its an electrical issue?

[Dr_Snooz]

Well, if it operates great, sporadically, then you don't have leaks. I agree with Old Blue that it sounds electrical in nature. The Honda manual has a real good A/C troubleshooting flowchart starting on p. 23-8 (at least in my '89 manual). I'd say proceed carefully through it and see what you find out.

[Oldblueaccord]

Check the 2 wire plug that goes to the compressor it hangs low and could be corroded and need to be cleaned up.


wp

[nelson20]

Checked the connection under the compressor, it looked pretty clean - disconnected and reconnected it. Replaced the diode with no improvement. Replaced the pigtail connector on the low pressure switch, but not the switch itself - with no improvement. The tube that's supposed to get real cold doesn't get real cold... while the system actually works. The car idled and the AC ran for 10 minutes while it sat but that insulated pipe never got cold. Would that be low pressure causing that pipe to not get cold? I still don't get why it'll work sometimes and others it won't.

Thanks for any responses.

[Mod14]

I own an '89 lxi accord and just went through essentially the same dilemma as you are. Eventually, your AC will quit working altogether and you will start blowing out your fuse that controls your AC/Fan switch panel (which happens to be the same fuse that operates the rear window defroster). The fan will still work but no cool air. Your problem is the Keihin compressor and to fix the problem, you will have to replace it. Believe me, I made all the changes and replacements recommended here. The Keihin in the long run just doesn't tolerate R134, et. al., and is likely heating up and will eventually lock up. You'll have to switch to a Nippon Denso compressor but you'll have to make alot of changes to the existing system to convert to this brand (different mounting bracket, different hoses, belts, etc.) You'll find it is best to go ahead and bite the bullet and buy a conversion kit from Majestic Honda for 623.00 and be done with it. Be sure to replace your expansion valve while your at it too. Good Luck!

[nswst8]

I ran R134a in a Keihin since 1997 I just did a compressor replacement to Denso only because I got a full conversion kit off ebay a couple years back.

It was the suction side on the compressor that had the leak (Its under the compressor so difficult to see)

The rough idle is because of the idle control valve probably just needs to be cleaned as I did mine and it idled alot better.

Just replace the seals and you shold be good to go. Now if the a/c cools better on the highway than in the city more than likely the compressor is getting weak swap it out.

Best way check if you still have a charge is to put gauges on it. Gauge valves shut. the pressures should equal outside temperature give or take a couple of degrees. example: 85-95 degree outside temp, 85-95 psi High side and 85-95 Low side equals full charge

[nelson20]

Just thought I'd give an update...
Don't ask me why or how, but the compressor just started working on demand since the beginning of August. I didn't do anything further to it since my last post. Actually, the one thing I have done is kept it on "Fresh" air all the time instead of recirculating the air. I'm afraid to push that button in fear that one little thing might cause it to stop working again. Whatever. Until I can afford the conversion kit I hope this one holds out.

I'll look into cleaning the idle control valve to help my idle. It's hesitating when I accelerate now too - even without the AC on (not as much with higher octane fuel). The websites search isn't working now so it'll have to wait since I like to research stuff before tearing things apart.