Thx, L
Look at the relays just behind the LHS headlight. The harness connections can get corroded. Check that the belt that drives the compressor is not loose.
Most likely however the system has depressurised. There's two (tire type) valves: Low pressure, on the tube/hose near the firewall, and high, on the tube just in front of the power steering pump. Unscrew the high pressure cap, and press the valve MOMENTARILY. If you get a loud high pressure release, the system is pressurised. If you get a quiet hiss or no sound at all, the system is low or depressurised, which is why the AC does not work.
Partial depressurisation occurs when AC hose O-rings have deteriorated, and should be replaced. Often happens during winter. Full depressurisation occurs when you have a corrosion hole leak.
An AC shop can do a vacuum test to see if there's any leaks. If the system still has some pressure, you may get by with a simple repressurise. Just be aware that it will leak away again in a few months. Cost is about us$160.
If there's no pressure, then you need to find which part has the hole. An AC shop can easily identify a hole. Its most commonly the condensor in front of the radiator, but the two hoses can be problems too. Check for prices of these parts from a wrecker (93-95 parts are all the same) then check the new price. ($$$$$$)
If its just the O-rings on the hose ends, then the AC shop needs to a) R/R the hoses and replace the O-rings b) replace the drier cannister (mandatory) next to the LHS strut tower. c) vacuum and repressurize. Should cost in the order of us$250.
It MIGHT be the compressor. If the AC shop says this is broken, get one from a wrecker. I have one here from a 94, in perfectly workable condition (came out of a working system).
Stewart DIBBS, Ottawa, Canada
Stew, I bought a small AC recharge device and connected it. The guage on this device indicated I was full, so I did not recharge it. Do you know of a relay involved in this? It is looking like either the compress clutch(maybe) or something is not turning it on. I did connect a volt meter to the wire going to the compressor and turned it on and got no voltage. Any thoughts?
thx, L
OK, you sound like you use tools, and I just happen to have my circuit diagram handly.
On the top of the drier canister is a triple pressure switch. If the AC pressure is within spec, this switch is closed. Pull the connector and check with your meter. If its open, the compressor clutch won't engage. You can't replace the switch without depressurizing the system, but you can just jump the wires if necessary. There should be +5V (from the ECU) on one of the switch wires.
There's another temperature switch on the compressor itself, and opens if the gas temp gets too high, disengaging the compressor clutch. I've never seen one fail.
There's a relay (the first relay behind the LH headlight, next top the inner guard) for the compressor clutch, and a 10A fuse that appears to be in the panel under the dash, to the left of the brake pedal. The relay group gets all sorts of water on it and the connections corrode. Pull the assembly out and check.
You can test the compressor clutch by undoing the connector in the cable that comes of the compressor, and applying +12V directly to the RED-BLACK wire (other is ground). If the clutch is OK you'l hear it click, and if the engine is idling, it should slow down.
regards, Stewart DIBBS
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Stew, I was having trouble finding some of the things you mentioned. However, I beleive we fixed it. I was checking fuses and found nothing labeled AC, no fuses blown btw. I also removed connectors etc. and reseated them and the compressor kicked on. Keep an eye on this thread I will be sending a picture of the car engine bay. When you get a moment could you point out some of the different AC subsystems drier etc.? I have the base line model car, I believe AC is the only option on this guy. Nothing special, but good gas mileage. Also, the relay you mentioned seems to be up in front of the radiator/condensor to the left (drivers side) head light?
I wanted to say I appreciate your update (to the thread) and patience.
Lessons learned, reseat all connectors first.
thx again,
Larry
Hi L/Stewart,
I have a 99 Mirage and i am facing the exact same problem. I did the High Valve test the system is pressurized. Can one of you explain where i can get some online technical help to reseat my connectors. If one of you can take the time to explain it to me .. it will be great too.
Thanks in Advance!
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