AC blows cold air sometimes, sometimes not

[EL SHO]

hey everyone.. seems I've got an issue with my AC. Sometimes when I turn the AC it will blow out cold air and sometimes will not. Obviously when it blows cold air I can see/feel that the AC compressor is kicking in and is not when blows warm/hot air.

When is working correctly I can use the AC all day long and it will be just fine, no symptoms like when is low on refrigerant that the AC clutch is kicking in and out. One time it didn't work but I kept on switching on and off the AC until I felt the compressor kicked in and it worked all day after that.

Besides checking again the refrigerant level, what would be another cause for the AC clutch/compressor not engaging and engaging sometimes?

I don't know much about AC systems, but is there some kind of valve preventing the refrigerant from getting to the compressor or is there some kind of relay not activating the compressor?

Any thoughs?

 

[rubydist]

typical symptom of clutch gap that is too large - works fine when cooler, not when hot. search for shimming the a/c clutch here on the forum - there are threads that detail the repair, which is not difficult.

 

[jelloslug]

The pressure valve may be on the way out.

 

[EL SHO]

I just found the thread to the clutch re-shimming, it seems not that complicated that I might give it a try. Thanks rubydist!

jelloslug,.. where is that pressure valve in the SHO? is there a way to check it or just replace it with another one and do a full discharge/recharge after that?

 

[jelloslug]

I just found the thread to the clutch re-shimming, it seems not that complicated that I might give it a try. Thanks rubydist!

jelloslug,.. where is that pressure valve in the SHO? is there a way to check it or just replace it with another one and do a full discharge/recharge after that?

There is an accumulator just forward of the compressor. The valve is screwed into the top with a 2 wire connector going to it. You can remove the valve without discharging the refrigerant. I would check the clutch shim first though.

 

[EL SHO]

cool.. I think I can work with that info, thanks a lot man!

I didn't really know about the re-shimming was possible to do in an AC cluthc; hopefully either the valve or the shim would get the AC going.

 

[itwonder]

Also may be marginally low on charge. Works sometimes, but other times the pressure is just low enough to trip the low pressure switch and turn off the A/C. +3 clutch gap is easy first check.

 

[JRA2000TL]

Is the compressor kicking on/off rapidly? That indicates a low charge too. If you want to re-shim the a/c clutch, you'll obviously need to remove the battery and tray; and you'll need a strap wrench or something to hold the pulley in place while you remove the clutch face. Be careful when pulling that face off. Those shim washers are small and can fly off and get lost easy.

 

[FamilySHO]

Ah, to be in Mexico and have to use the ac in my car....:sun:

 

[EL SHO]

well guys... I checked the car's AC compressor after getting out of work, literally out of work right down in the parking lot, I switched on the AC and the compressor wasn't engaging at all. Since I cant reach the clutch's face with my hand I remembered that I carry the car's club that I use to put on the steering wheel at night and with that I tapped the clutch's face a bit and pressed it against the pulley and what do you know it started turning!
I checked how the air was blowing out of the vents and it was cold! I switched the AC off and then on again and the compressor didnt engage, I did the same steps again with the steel handle and once again it started spinning.
So... I think this sounds that it does need the re-shimming then, right?

I drove off with me AC working. It wasn't that hot yesterday but enough to use the AC, around 80* but today we're having temps in mid 50*s and raining... that's how temps vary here in Monterrey, Mex.

 

[rubydist]

yes,you need to re-shim the clutch.

 

[itwonder]

yes,you need to re-shim the clutch.

X2 reshim it.

 

[EL SHO]

Well I just finished doing the reshim on my SHO's AC compressor and guess what... It's now blowing cold air and the clutch spinning as it should!
Couple of things I found out were that the compressor had 3 shims instead of 2, it had 2 thicker ones and a slim one so I took one of the thicker shims and left the one thinner along with the other thick shim, put back in together, turned th AC on and it worked.
The other thing I found out was that, since my old battery was spilling acid it had almos covered the clutch in acid so it had all that acid crud inside, I sanded and cleaned the clutch and compressor the best I could... word of advice, Never let too much time to pass to replace your battery when small signs of leakeage are found.

All in all seems everything work. Thanks a lot to you all man for the advice!

 

[SHOspazz92]

Glad to hear it!

 

[Huy Phan]

Well I just finished doing the reshim on my SHO's AC compressor and guess what... It's now blowing cold air and the clutch spinning as it should!
Couple of things I found out were that the compressor had 3 shims instead of 2, it had 2 thicker ones and a slim one so I took one of the thicker shims and left the one thinner along with the other thick shim, put back in together, turned th AC on and it worked.
The other thing I found out was that, since my old battery was spilling acid it had almos covered the clutch in acid so it had all that acid crud inside, I sanded and cleaned the clutch and compressor the best I could... word of advice, Never let too much time to pass to replace your battery when small signs of leakeage are found.

All in all seems everything work. Thanks a lot to you all man for the advice!

my toyota has the same issues. is it something you can share how this gets done? U Tube video or some links ?
Thank in advance

 

[Devin]

Thread resurrection and it isn't even a Ford? tsk tsk