Meb2383

1999 Lexus ES300 AC light is blinking.
I have changed the following:
Clutch relay
Compressor
Cabin filter
Before changing the cabin filter I would just get a blinking light and no AC. After I put in the cabin filter the AC worked with no blinking light. turned off the car and back on pressed AC on and got the blinking light again no AC...

When I replaced the compressor I replaced the drier. Had the system vacuumed and recharged. But the AC still wouldn't work. I am stumped and looking for ideas on what I should check next? Fans, AC control unit, wiring?

Any help would be great.

Thanks

Fritz330

https://www.clublexus.com/forums/es3...t-working.html

Mythotical

Sounds like the expansion valve is plugged to me. Here is a link on how to fix.

https://www.clublexus.com/forums/es30...placement.html

Meb2383

Mythotical thanks for the link, but it doesn't go to a good page I get and error.

Also is there a way to check the Expansion valve before I try to change it?

Thanks

Meb2383

Fritz330 thanks for the link, but I already changed out the following:

Magnetic Clutch relay
Compressor
Cabin filter

After the Relay and compressor I would still get the blinking light. I took in to my mechanic and he couldn't get the compressor to full engage unless he routed power straight to the compressor.

After I changed the cabin filter (actually there wasn't one to take out) I got the AC to come on and stay on. but once I turn the car off and then back on the light started blinking again.
I ran the AC diagnostic to get codes yesterday and I got 00. So no help there.

Does anyone have a trouble shooting chart for the AC system? Is there on in the Service Manual?

Thanks

PFB

When the AC does work, do your fans come on?

hzt30

This could be an A/C amplifier/control problem. The A/C amplifier senses something is wrong with the System and shuts down the compressor and blinks the light.

Mythotical

Sorry, I must have copy pasted it wrong. Try this one.

https://www.clublexus.com/forums/es3...placement.html

As for checking the expansion valve, have your mechanic hard wire the compressor (for testing only!) and hook up a set of manifold gauges to observe the pressures. A low side pressure between 26-45 is normal, and at the same time, the high side pressure should measure somewhere in the range of 255-315. If while the compressor is running and the low side drops below 18 psi while the high side looks normal, I would suspect the expansion valve is clogged or stuck closed. If the High pressure side goes lower than 195 but the low side is anywhere from 0-195 then it could be a bad compressor, low charge, compressor not engaged, or the expansion valve is stuck open. Really nothing can even be guessed at until you have a reading on those pressures.

Mythotical

Also have your mechanic run 12v and ground to the coil on the a/c clutch relay. If the clutch will not work then have him/her start looking for a broken, shorted or missing wire in the harness between the compressor clutch and the relay panel.

P.S. a mechanic who is well versed in A/C service/repair and diagnostic should know these things, so if you can not get anywhere with this guy, perhaps it's time to see a specialist. Or me if you happen by my neck of the woods.