A/C keeps shutting off - Toyota Nation Forum : Toyota Car and Truck Forums

89_3SFE · 07-21-2005, 10:13 AM

I've got an 89 Celica GT and after I've been driving the car for about 15 minutes, the A/C shuts off and the light on the A/C button starts flashing. It usually happens when I'm in gear waiting at a stop light. If I slap it into neutral, it does nothing. Can anyone tell me why it does this or how I can fix it, if it's anything really bad? The A/C works great, so I know it doesn't need more refrigerant. Thanks everyone!

Pineapple · 07-21-2005, 10:28 AM

How do you know it doesn't need refrigerant? Do a pressure test on both high and low end and make sure its within spec. Flashing A/C light mean something wrong with the system. Check the A/C pressure switch also.

lcarocha · 07-21-2005, 12:32 PM

You could also have a faulty RPM sensor on the compressor.

rutuger85 · 07-22-2005, 05:18 PM

Hey, I've also got an 89 GT and I've been experiencing the same problem with my A/C. It wasn't working at all but then I charged it and it was fine except for the fact the light will turn on and off. Does it come on when you flick the button? Because mine does and bumps in the road will turn it on and off as well. If anyone is out there with a clue to this problem help us out because I've seen first hand that the physical system is sound and its got to be electrical.

lcarocha · 07-22-2005, 06:09 PM

The light is supposed to be ON when the compressor is engaged. If the light starts blinking after you hit a pothole or something the you have a faulty RPM sensor. The sensor is located on the underside of the A/C compressor and is replaceable. When it's in its possition it looks like the O2 sensor screwed to the manifold with 2 wire coming out.

rutuger85 · 07-23-2005, 10:17 AM

Then why is it that I can keep flicking the button and it will eventually stay on and sometimes hitting the dash has the same effect?

lcarocha · 07-23-2005, 11:07 AM

Because the sensor will eventually pick up the signal and "tell" the ECU that the engine es runnin and engage the A/C comprressor, you will be able to keep on doing that......for awhile. After some the time the A/C will just not work.

Take it from someone who can't live with out A/C and has changed almost 80% of his A/C system.

rutuger85 · 07-23-2005, 12:29 PM

Ok well will I be able to buy a new sensor from any auto parts place?

lcarocha · 07-23-2005, 02:58 PM

Not sure, I live in a place where I have to buy OEM sparkplug wires because there are no aftermarket brands for the Celica