A/c light blinking

[Mike the Wino]

I like to use my a/c to speed up windshield defrosting on my '03 4Runner during the colder months...this past winter my a/c light would start flashing (and the compressor wouldn't engage) any time the outside temp was below around 40 degrees. Now that the temp is consistently above 40, this condition no longer exists...i.e.: the light doesn't flash and the compressor engages just fine. I have read the thread at http://www.toyota-4runner.org/problems-warranty-issues/17634-c-light-flashing.html and the associated yotatech thread, but my situation isn't quite the same as described in those threads. I have also read TSB 011-05 and checked the relay mentioned in those threads, and I do have the wrong one installed from the factory.

Has anyone else experienced this particular condition, and if so will changing the MG CLT (magnetic clutch) relay fix this?

 

[03_4x4Runner]

I do not know if this would affect it but do you have the proper amount of Freon in the system?

 

[Mike the Wino]

Yes, I do. And you're right, from everything I've read the blinking light is not an indication of the system needing service as far as flush/fill is concerned. It only blinks when the compressor fails to engage for some reason or another.....

 

[03_4x4Runner]

The cheapest thing to do is put in a new updated clutch relay. I changed mine several years ago just because I did not want to wait for the flashing ac light and not have ac. It get to 120 degrees here at times in the summer. I do not know if mine would not work at 40 degrees because it never gets that cold here.

 

[Johnny4runner]

Try swapping the AC relay with one of the other relays in the control box. I narrowed down my issue to the AC rely by swapping it out with a similar relay. I forget which relay it was but I remember things I could go without whatever it controlled for a while to test the AC relay.

 

[Mike the Wino]

That's a good idea, but because the temps are above 40 and everything seems to be working fine (and the light isn't flashing), swapping them out is going to have to wait until next winter...

...I was just wondering if anyone else had experienced this exact same condition, and what fixed it. In the other posts I've read, the flashing light syndrome didn't seem to be temperature dependent.