Problem: AC Working intermittently

[rick_spiff]

The ride: '89 Accord SE-i

The problem: The AC system only works when "it wants to." It cools real, REAL nice when it's on... which isn't very often. Sometimes it doesn't come on at all, even though the light is on and the condensor fan is running just fine. Randomly it will come on WHEN YOU TURN ON THE SWITCH OR FAN (i.e. move the fan setting from 'off'). After a while it may switch off. Does not matter at all if you're cruising on the highway, exiting, entering, city driving, etc.

It's been riding 106 out here for the past two weeks and this is getting _annoying_.

On my list of things to check are:

1. Voltage at compressor clutch (inadequate voltage to engage?)
2. All grounds (loose wire?).
3. The refrigerant pressure switch by the dryer (faulty sensor?).
4. Unusual resistance in the wiring (bad connection).

Anything to add? How do I test the pressure switch? How do I test for intermittent compressor clutch failure? How do I test the AC diode and relays?

Any help would be greatly appreciated as my family and I continue to melt through this summer ;)

[cruznz]

faulty thermostat maybe

[DBMaster]

I had a similar problem just before I replaced the system. I had adequate freon, voltage at the clutch, condenser fans working, etc. I had the Keihin (POS) compressor, by the way. Mine would work great when on the highway, or for a while after starting the car. Once the engine compartment got hot from sitting in traffic the compressor would not engage and it got toasty really fast.

Check the gap between the pulley and clutch plate. Mine was just slightly wider than tolerance so I guess once it got hot enough the gap was just wide enough to keep the magnetic force from being able to pull the clutch plate in. The thing would hold a socket wrench against it while energized, but it wasn't strong enough to work across the gap. The part can be shimmed to get back a narrow enough gap. My problem was that my front seal was leaking, too, so there was no point in spending the $200 to have the shop pull the clutch apart and change the shims.

This information is all in the shop manual, BTW.

[rick_spiff]

Hmm... that's a new one. If the voltages and sensors check out, I guess I'm checking on that clutch then.

Talk about oddball problems.

Thank you for the pointers anyway.

[DBMaster]

It does sound oddball, but the Honda shop I took it to told me it was common. It's just something you can't fix at home without special tools for pulling the clutch.

I think usually by the time this problem occurs something else has forced the replacement of the compressor.

Check your clutch coil to make sure. When it is energized the clutch should either be engaged or you should be able to get something made out of steel to "stick" to the front of the compressor (it is a big magnet).

[rick_spiff]

The connundrum I face now is that if it is indeed the clutch, would be cheaper/safer to junk that compressor and dryer and simply rebuild the one from my spare engine (the SE-i is a Keihin, the spare is not), and put es12a or something in there.

Anyway, if the shop can fix it with minimal troubles, then I'll go back to my rebuild and address the AC system as a whole later. ;)

[DBMaster]

The compressor I have now is a Sanden. It was part of a $750 kit from Honda that included the drier, hoses, compressor, bracket and belt. (Turns out it is exactly the same belt I had before). Anyway, I still stuck with R12 for performance issues. I do a lot of stop and go driving and like it COOL.

The Keihin has shaft seals made of Viton which will not retain their integrity using R134a. As far as which R-12 replacement refrigerant is best...There are so many opinions on that.

[POS carb]

Originally posted by DBMaster
The Keihin has shaft seals made of Viton which will not retain their integrity using R134a. As far as which R-12 replacement refrigerant is best...There are so many opinions on that.

I can vouch for both, my car used to fog the windows with R12 but after I started running R134a it wouldn't drop below 50* inside and then the compressor started making this rattling noise after 2 months or so and it siezed up.

[Mac]

If your compressor is indeed bad, your best bet is to rebuild or replace compressor and dryer. Then vacuum the system and recharge with R 12.

[Vinny]

Might also want to have the system flushes on it if you've been having alot of problems. Iknow most places i see selling compressors and A/C parts in general only warranty the parts if you change the dryer, expansion valve, and have the system flushed and vacuumed.

[accordlxi2.0]

or just get the denso i heard they're pretty damn good.
i read 'bout the 2 comp. after i put in r134 and i'm lucky to find that it's a denso.

[rick_spiff]

A solution presented itself (now that it's too cold to matter).

I have a spare denso from my old engine. Since I'm ripping of the tranny/head, I'll just take the AC comp. too and charge the system with r134 or something. Everything but the compresser clutch itself checked out, so new compressor!

[AdAm88lxi]

My car was doing the same thing, The a/c only kicked in when I had suffered long enough and the car decided to give me a break. Now the pos compressor locked up. It's 40 degrees out side but it's still the point that I have to fix that now too.
I couldnt really see(mainly because i didnt look too hard) but what does the a/c belt run, or can I just cut the thing off? It's a 2.0 fi

[rick_spiff]

You can cut it and it will run just fine, but remember that the pullies that the AC belt normally runs around will begin to rust w/o any belt running over them. Might take a few months, and a VERY light coat of oil will protect them, so, go ahead.