Ac Problem

[chargerucd]

Hello guys,

Yesterday i was driving home and sincew it was hot, i put on the air, it didn't work as good as i would like. but i still left it on, the air got hotter so i look over and saw the AC buttton flashing, i didn't know what to do so i turn the AC off, thenimmediately back on. At that point the belt made a screeetching noise as if the compressor has seized, then i turned the AC off again, that scareme a bit as i smelleed some burnt rubber. but i went home OK. today in the morning wen i left for work, i "tested" the AC by turning it on, i didn't get the "seized" effect, but still got the smell.

so, question is have yoiu guys had this? do i have to replace the compressor now? or can i just take it to get "serviced"

don't know which way to go from here now.

thanks a lot for the help.

[wwest]

Not enough contact friction between the drive belt and the compressor clutch pulley. That could be due to a drive belt problem or a failing bearing in the compressor.

[akkuma2k]

what year car?

[chargerucd]

This is a 1996 car i just got 3 months ago.

maybe it was "low" in refrigerant and my using it killed it?

let me know what you think.

[monarch]

Screech noise + burning smell is a symptom of a bad magnetic clutch on the compressor that causes the compressor belt to burn, but the compressor itself could be fine, especially if there was at least some fairly cold air coming out the dash vents . The clutch can be unbolted from the compressor and a new one installed, but a special tool is needed to keep the clutch from rotating as you try to unscrew the clutch mounting bolt. An AC shop or Lexus dealer could do this, BUT, 9 times out of 10 they will either say you need a whole new compressor (lots more profit for them) or insist it would be a waste of time to just replace the magnetic clutch. I can't think of any more corrupt and dishonest segment of the automotive repair business than the AC repair segment. The huge advantage (in $cost) of just replacing the magnetic clutch is that the refrigerant in the system doesn't have to be removed and rechanged and the compressor doesn't have to be removed either (if there is enough working room to remove the clutch). You can either get a new clutch from a dealer or a used one from a recycler like taprecycling.com or a neighborhood auto junkyard if you live near a big city.

[chargerucd]

thanks for the info, i'll look into gettting a new clutch.

Also since the AC light was blinking is there a specific reason whi it does that? is there a code i can get to find out that's going on? or would the light go off after replacing the clutch if the clutch is the problem that is!)

let me know

thanks again

[wwest]

The A/C light blinks when the A/C compressor is not turning at the rate appropreate to the engine RPM.

With A/C enabled the on and off cycling of the compressor is controlled almost exclusively by the multi-function pressure switch.

The pressure switch is on the liquid, high pressure, side of the refrigerant cycle.

If the liquid side pressure drops TOO low that is an indication that there is not enough refrigerant in the system to provide cooling and the compressor will not run at all in that case.

When the high side pressure drops to a low enough point that indicates that all of the liquid refrigerant has not be used via cooling the A/C compressor will kick in and pump the gaseous refrigerant in the low pressure side into the condensor under enough pressure that it will "shed" enough heat via the condensor heat exchanger and return to a liquid state.

That will obviously result in a rise in pressure on the liquid, high pressure, side of the system and once the pressure there is high enough the A/C compressor clutch circuit will be opened.

So the pressure switch serves three somewhat independent functions.

A) It prevents the compressor from operating at all if the refrigerant level is TOO low.

B) It engages the A/C compressor clutch circuit when the liquid refrigerant is almost depleted.

C) It disengages the A/C compressor clutch once the high side pressure has risen to a level significantly higher that the pressure was at the point of compressor activation.

Screech noise + burning smell is a symptom of a bad magnetic clutch on the compressor that causes the compressor belt to burn, but the compressor itself could be fine, especially if there was at least some fairly cold air coming out the dash vents . The clutch can be unbolted from the compressor and a new one installed, but a special tool is needed to keep the clutch from rotating as you try to unscrew the clutch mounting bolt. An AC shop or Lexus dealer could do this, BUT, 9 times out of 10 they will either say you need a whole new compressor (lots more profit for them) or insist it would be a waste of time to just replace the magnetic clutch. I can't think of any more corrupt and dishonest segment of the automotive repair business than the AC repair segment. The huge advantage (in $cost) of just replacing the magnetic clutch is that the refrigerant in the system doesn't have to be removed and rechanged and the compressor doesn't have to be removed either (if there is enough working room to remove the clutch). You can either get a new clutch from a dealer or a used one from a recycler like taprecycling.com or a neighborhood auto junkyard if you live near a big city.

Sorry, but the first question to be asked is whether the drive belt is slipping on the pulley or is the clutch surface itself slipping?

The easiest way to find out is to have someone rev the engine up to about 2500 RPM and then turn on the A/C while you are carefully watching the A/C compressor clutch and pulley assembly. Assuming the squealing "event" repeats, is repeatable, if the clutch pulley turns with the belt travel then the clutch has failed. If the pulley does not turn with the belt travel then the belt is slipping.

Does the squeal occur, by chance, when you turn the stearing wheel hard/quickly while parked? If so that might mean your drive belt is not tight enough or is failing.

[abrarcool]

The Toyota compressor is fairly common on all its cars and therefore you should be able to get a nice deal at a junk yard and installed cheap too 50$ for compressor i would say 100 $ for replace and recharge.Then maybe it might be more depending on the mechanic but that sounds fair, and if you want you should be able to do it too replace the O rings when u replace the compressor and compressor oil.

[chargerucd]

Hello,

Sorry i was out on a trip and just checked the car by tuning it on, open the hood and have someone turn on the AC switch as i looked th the compressor, Once the Clutche engaged, the AC pulley was "LOCKED IN PLACE" and the belt was slipping on it. This meand that the whole AC comprecsor must be replaced right!!

thanks a lot for the help.

Chargerucd

The Toyota compressor is fairly common on all its cars and therefore you should be able to get a nice deal at a junk yard and installed cheap too 50$ for compressor i would say 100 $ for replace and recharge.Then maybe it might be more depending on the mechanic but that sounds fair, and if you want you should be able to do it too replace the O rings when u replace the compressor and compressor oil.