88 Camry A/C help

[bluedevil]

I have an 88 Camry LE, 2.0L that I bought last September. I got it cheap and knew the A/C didn't work, but in September that wasn't much of a problem. Now that summer is rolling around I need to get it fixed. When I turn the A/C on, the compressor kicks on, but it shuts off about 5 seconds later and the A/C light on the dash starts blinking. I haven't left it on for more than a few minutes, but it never stops blinking and the compressor doesn't kick back on. I took it to a local shop and they told me the compressor needs to be replaced, but another person I talked to a few days later told me that was almost certainly wrong since the compressor does kick on at first. I searched through some old posts here and saw mention of a rev speed sensor that could be causing this problem, but I have no idea where to locate that. If anyone has any suggestions that could help me fix this problem I'd appreciate it. I'm not a great mechanic, but I can do most tasks if I have decent directions to follow. Thanks in advance.

[cheezthis]

Well...when I had my old 88 Celica w/the same 3SFE engine in it, it had similar problems. The A/C would turn on, flash and turn off. First time, it was the idle up switch. A few years later, it started doing it again. I never did figure out what the problem was then. I simply had to turn it back on when it would turn itself off.

That's the best I can do for now. I haven't owned that car for 3 years, so it's been awhile. I just remember the A/C being a real headache.

[MCTOY]

Could be idle up switch,.... but really sounds like you have low/no refrigerant pressure and the low pressure switch is doing it's job by shutting down the comp. B4 damage occurs. Jump out the low pressure switch with a paper clip and see if it will stay on. (WARNING: DONT LEAVE IT ON LIKE THIS FOR MORE THAN A FEW SECONDS JUST TO VERIFY THAT THIS IS THE PROBLEM!) If it runs longer than 5 seconds (like B4) you probably need refrigerant, or possibly a faulty low pressure switch. Try a can of R-134 first. Which brings us to part 2 of the problem....If you have no refrigerant then, you have a leak SOMEWHERE. Check around all the hose fittings for signs of oil/dirt, or you can have someone check for leaks with an electronic detector.
Just some ideas...
MCTOY

[bluedevil]

I should have mentioned in the first post that I checked the refrigerant level and it is fine (at least according to my cheap AutoZone gauge). Where is the low pressure switch located?

[toyrolla]

Originally posted by bluedevil
I should have mentioned in the first post that I checked the refrigerant level and it is fine (at least according to my cheap AutoZone gauge). Where is the low pressure switch located?

On the lower left side of the condenser, by the receiver.

The receiver looks like a small canister.

You will find the dual pressure switch. The high pressure switch is the switch that connected directly to the canister. The low pressure switch should be the one next to it.

By the way, what gauge did you get at Autozone to check your refrigerant level? I think I better get one for my car.

[bluedevil]

The gauge came in a box with 3 cans of R134a. I don't recall the exact brand though.

Thanks for the help. I'll go take a look at that later today.

[toyrolla]

Originally posted by bluedevil
The gauge came in a box with 3 cans of R134a. I don't recall the exact brand though.

Thanks for the help. I'll go take a look at that later today.

Oh I see...you got the converter kit then? Cool...

I need to do the same for my 88 I4, no A/C in that oven box.

Good luck with finding the switch....hope you fix your problem.

[bluedevil]

Ok, I found the switch, followed the wires back to the connectors by the end of the battery (they sure aren't easy to get to are they?). If I followed you correctly, the low pressure switch had the white connector and high was blue. I unhooked the white connector and put the paper clip in there and tried it, same thing (compressor turns off after about 5 seconds). Just to check I repeated the process with the blue connector, no different. I only had one paper clip so I couldn't do them both, but I assume it wouldn't make a difference. Any more ideas?

[MCTOY]

Try jumping the low pressure switch with the high pressure switch unplugged and jumped also. It is possible that you have an overcharged system, or air and refrigerant mixed (If system was charged without first evacuating it and putting it in a vacuum) causing high pressure switch to shut it down.) The low pressure switch opens if you are low and the high pressure switch opens if the pressure is too high. If you eliminate the low pressure switch possibility via the jumper, and unplug and jump the high pressure switch and it still doesnt work with them both jumped, you either have a gross overcharge (Discharge some refrigerant and try again) or the compressor is bad (Clutch or valves) By the way: the guages that come on the cans are very inaccurate. They only show the presence of refrigerant (or pressure, which could be regular air) , not the amount or condition of the refrigerant. Only accurate way is with 'REAL' guages and the system running.
Hope it works out for you
MCTOY
PS, Just noticed that you DID try the high pressure switch. Doesnt sound good (Comp) try discharging some refrigerant, maybe its grossly overcharged, otherwise it sounds like the comp.

[chronoti]

hummm or it could be that there is a block in your line since you have a cheap setup you cant check the high side pressure .... take it to a shop and jump the low pressure switch and if it still runs check the high pressure if it gets too high then you need to check the lines the dryer might be cloged or the expanson valve (i might of mixed the terms for 2 types of systems there but hey my dad went to school for this not me) also might be the thermostat on the evap that shuts off the compressor when it gets too cold ....