AC Light Blinking - Toyota Nation Forum : Toyota Car and Truck Forums

stope4 · 11-01-2009, 01:26 PM

I have a 96 avalon. I replaced my compressor after 150K miles and 13 years. The compressor or maybe the clutch burned up. Had a buch of melted black stuff coming out from under the cluch area. To repair I have replaced the compressor, drier and expansion valve. I was able to hold a vacuum, removed some of the oil from the compressor and charged the system with two then three cans of pure 134a. The problem, after the ac is on for about 5 seconds the compressor shuts off and the ac light starts blinking. I replaced the amplifier and control head to no avail. I reversed the relays under the hood. Light still blinks. I am wondering if my low pressure switch is bad? What about the revolution detecting sensor. The ohms across the RDS terminals is at about 113. Book says 165 - 200 but I have read where 100 - 130 is good. Don't know which is correct. I have jumped the compressor to the battery and the ac blows cold. Just don't know how to keep it running. Any ideas?

blkavalon · 11-01-2009, 08:25 PM

i am looking forward to peoples responses on this regard. one day it happen to me too, my AC light start blinking and no AC. but it never happened after that im still wondering what happen that day.

for your case do u have enough refrigerant on your system? compressor shuts when there is not enough refrigerant.

kevdude · 11-02-2009, 06:25 AM

Mine did the same thing when it was low on refrigerant. Serviced it up and the blinking light went away.

stope4 · 11-02-2009, 08:40 AM

It's not low on refrigerent. Put 30 oz in just like the book says.

stope4 · 11-05-2009, 08:16 AM

Well, I guess this is touger than expected. I jumped the hi/lo switch, and I jumped the compressor. I replaced the amplifier and the controls. When I jumped the compressor it stayed on but obviously it can't run it this way. The compressor I bought didn't have the same connector as my oem compressor so I cut the new compressors connector and installed the original round connector. Could this wire I cut, which is the wire to the compressor that goes in behind the compressor clutch, possibly be a resistor wire?

stope4 · 11-14-2009, 10:11 PM

Got this sucker working today. After talking with a mechanic locally, he told me that sometimes Toyotas just want a factory OEM compressor cause the computer is looking for certain signals from sensors in the compressor. based on this, I called the place I bought the compressor, Discount AC Parts, and told them I couldn't get the compressor to stay on. Told them I had to cut the connector because theirs wasn't the same as the factory one. They were very friendly and told me they had a factory OEM compressor in stock but that it would cost $40 more. I went ahead and purchased the factory OEM compressor. Turns out, when I received the OEM replacement, it not only had the correct connections but it also had a new Magnetic Clutch Sensor (MCS) already installed in the bottom of the compressor. The first compressor I purchased from them required that I remove the MCS from my old compressor and install it on the new one. The MCS could have been the culprit but I couldn't get a good reading. Why anyone would sell a compressor without this is beyond me. Hell, Toyota told me the part is not even available unless you buy a new compressor. Regardless, everyone in the market for a new compressor should ask if the MCS is included. It's the part on the bottom of the compressor with two wires soldered to the bottom where they look like they are coming out of the compressor. It is not connected to the wires coming from behind the clutch. Went ahead and replaced the drier again to be safe, evacuated air and charged with 134a. That baby is running like a champ.

blkavalon · 11-14-2009, 10:47 PM

thanx for the info. happy that you figured it out.