Celica Forums General Discussion General A/C Stuck On. Bad Compressor?

I've got a 2002 GTS automatic trans. Trying to diagnose an issue and would love some feedback.

Last week my fresh air/recirculated air selector switch broke off on the inside. I can move it from side to side but it doesn't feel like it's connected to anything anymore. I assume this is completely coincidental and unrelated to my issue, unless the a/c in these Celicas is set to auto depending on this selection.

So, a few days after the selector switch broke, I turned on the car and the RPM fluctuated wildly, threatened to stall, and corrected once I pressed on the accelerator. Upon troubleshooting this, I've found the following:

1. This RPM fluctuation only happens if the blower is turned on. Unfortunately, I cannot tell for sure if it is a blower or compressor issue because the a/c seems to be stuck on. As you know, our a/c selector is just a button, not a manual switch. The a/c light is blinking, and I have tried pressing the button, and even holding it down, and I cannot get the car to switch from a/c to heat. I can turn the temp all the way in the red and the a/c light blinks as soon as I turn the blower on.
2. There is plenty of air coming through the vents, so I think this is not a blower issue.
3. There is a definite gear grinding/straining sound and a burning smell.

I suspect a/c compressor or a/c clutch... any way to tell for sure without paying mechanic for diagnostic? And why would this issue cause the a/c to be stuck on? If I pull the fuse for the a/c, will the heater still work and get me through to next summer when I'll be forced to fix an a/c issue? Any other way apart from the fuse to get the a/c unstuck?

Hello,

Okay to better understand this:

Which AC/Heat panel do you have? do you have the digital version with all the buttons, or the manual that has the slider at the top,
and the 3 knobs to direct air, temperature, and fan speed?

Looking at the cabin temperature AC/Heat panel.
If if I remember correctly the switch from inside air and outside air is the very top slider on the manual AC/Heater control panel
I broke that slider on my Celica to change the air from inside and outside and it had no effect, except that it was stuck on outside and driving past cow farms didn't smell to pretty.
but the slider is attached to a cable that opens and close the flap in the white air box the Blower motor is attached to. that shouldn't really effect anything. At least it shouldnt.


the knob all the way on the right is to direct the air flow. there is a cable that goes directly the black air bx located directly behind the ac/heater control panel. if its stuck on defrost it will always run the AC to demoisturize the air to help prevent fogging as a safety concern (although when I was messing with mine it would blow cold air at the bottom center of the windshied and cause it to fog/condensate on the exterior of the windshield)

the middle knob is the blower motor control knob which is connected with a wire connected to the blow motor fuse/blower motor.

The left knob is the temperature control knob which deals with hot and cold. This a cable/wire that connects this knob to the black air box. this allows you to direct the air flow blow through the heater core, or the AC alternative to that the heater core. Often times the foam that would normally "seal" starts to crumble away and can cause issues like not properly closing the blend door or blocking you from opening it all the way. also if objects fall through the upper dashboard vents it can cause the blend door to get stuck.

the cables are hooked into place on the back of the air control panel, and are clipped to the side of the white and black air boxes. and then have a loop that slides on a peg. The clip holds the outer plastic that the cable resides in and the allows it to smoothly pull and push the peg to operate the doors.

If you don't have electrical heating and have a heater core like my 2000 Toyota Celica then you should technically have heat on all the time because it disperses the heat from the coolant circulating through the engine when the blower motor pushes air through it ( A tip if your engine is over heating from radiator fan issues, you can go a little further blowing straight hot air into the cab as this slightly cools the coolant in the engine). Pulling the AC fuse would and should only affect the AC only.

For the engine fluctuations. You said it threatened to almost stall when the blower motor is on?
is this when all lights are on our just engine on, ac on and blower motor on?
Unless your wires melted together and that could be the burning smell you mentioned, the only other thing I can think of to cause the engine to almost stall out is if your batter/alternator is really bad off. The reason i say this is if the AC clutch/pulley bearing was going out or seizing then you should notice the fluctuations at all times while at idle.

Back to the wires being melted together. I can't remember but i believe it is just one electrical connector that goes to the AC/Heater control panel that holds the blower motor power wires as well as the power wire to the electromagnet for the AC clutch. If for some reason the wires melted together or were sliced and making contact it is possible to always send power to the AC Clutch and the AC button couldn't couldn't regulate it, as well as causing a huge electrical drain when using the blower motor.


Is there a check engine code, or have you noticed any fuses blowing or keep blowing?




to check the AC/AC Clutch. pull the fuse (or the AC wire connector while the vehicle is off (Note: you shoudln't hear the clutch disengage while engine and key is off as it should already be off) and you should hear and visually see the AC clutch disengage. The AC Compressor should be located at the bottom right of the Serpentine belt pulleys. right by the front of the front passenger wheel.

I know that's quite a bit to read.

The gist is that you should be able to have heat regardless of the AC being on or not because the heat is always available it just needs the blend door opened to the heat side in order for air to travel through and carry the heat.

if your AC is always on: either the the mode is set to defrost the front windshield as a default, or its always sending power to the electromagnet to keep the AC clutch engaged or if it could possible be a broken or extremely rusted AC clutch that is stuck in.

the burning smell: Is that inside the cab or primarily engine bay?
it could be wires.


I have no idea what could cause the gear grinding noise at this time, with out further information

Then engine would only stall out on either

Too much engine load/strain
not enough gas
not enough air
or loss of spark


Manual vehicles (Disclaimer: I understand yours is an automatic) stall out because the engine doesnt have enough power with idle air and gas to move the vehicle and causes the engine to first spudder and then fully die out depending on how fast our slow you take the clutch. This can also happen if the serpentine belt pulleys bearings start to where out (This could be a grinding or scratchy noice hear in the engine bay) or when the battery and alternator can not keep up with the power demand of the all the accesories and it looses a bunch of rpm and attempts to stall.