AC light flashing, relay is good

[james.wetzstein]

Hello,
I've read the threads about replacing the relay and have done so. I have also replaced the cabin filter.
My AC light continues to flash continuously whenever AC is engaged.
I've checked for codes following the instructions:
Hold "Auto" and "recirculate" while turning key to "ON"
Codes display as "00"

It's a 2008 Limited with 140,000

If freon is low or the compressor is bad, shouldn't I get a code?

Any advice is most appreciated.

Jim

 

[toyo]

Low freon will not set a code. Hang tight, I'm thinking for ya!

 

[toyo]

What color was the old relay? What color is the new relay? Toyota has a TSB on faulty relays. The old part# is 90987-02022 and it is white. The new one is part#90987-02028 and is gray.

 

[james.wetzstein]

The new relay is grey, I can't recall the color of the old one. But I know that the new one is good, because I've switched it out with the foglight relay and the lights work and the AC still doesn't, even with the fog light relay (and the fog light s worked with their own relay before the switch)

 

[james.wetzstein]

and thanks for replying toyo

 

[Bossman]

Code "00" would indicate normal operation.

Can you describe any other symptoms for us?

Does the blower motor work, and can you change the speed (high, medium, low) of the air flow? Can you change between fresh and recirculating air?

It could very well be that you have lost refrigerant pressure somehow and an associated loss of volume of refrigerant. Might also be drive belt tension.

 

[james.wetzstein]

Yes, all other functions are fine Bossman. I checked the door functions as part of the diagnostic and it's all good.
The only malfunction is that the air that is blowing isn't cold and the light is flashing.

I changed the timing belt over Christmas, but the AC has been working fine since them--this is my daily driver, average daily mileage is 50 miles, so it's gotten plenty of use since the timing belt, serpentine change.

Thanks for asking.

 

[Bossman]

With a normal code and not blowing cold air (with drive belt tension and magnetic clutch relay seeming to be fine), my best guess will be low refrigerant.

Other possible suspect areas would show a code (e.g., compressor circuit, pressure switch circuit, air mix circuit, temperature sensor circuit).

 

[james.wetzstein]

Bossman and toyo, thanks for the replies. I'll look into refrigerant/leaks and post a follow up.

 

[james.wetzstein]

Well I did a little more reading and went out this morning with the instructions for the sight glass test. Wouldn't you know it? The AC blew cold and the sight glass test looked to be within spec to my untrained eye. I really dislike intermittent problems.

 

[dmalis12]

Well I did a little more reading and went out this morning with the instructions for the sight glass test. Wouldn't you know it? The AC blew cold and the sight glass test looked to be within spec to my untrained eye. I really dislike intermittent problems.

I am having the same problem. I replaced my relay (which was already grey and correct number) and I still get the blinking light. It's not all the time but more often than not. I'm going to try and use the A/C pro recharge kit and see if that helps. What is the Sight Glass test?

 

[toyo]

Next time the light blinks and will not work try turning it on using the Auto button. I have seen where this will work.
If your gonna charge it yourself make sure you don't overcharge it.

 

[dmalis12]

Next time the light blinks and will not work try turning it on using the Auto button. I have seen where this will work.
If your gonna charge it yourself make sure you don't overcharge it.

Any tips on charging. I know the AC pro has a pressure or fill gauge on it but this is the first time recharging the AC for me?

Thanks

 

[james.wetzstein]

A search on this site for "sight glass" will provide a link to a PDF. I'll post the link on this thread tonight when I get in from Scout camp.

 

[james.wetzstein]

sight glass test

 

[toyo]

I just read that PDF. I am not aware of #5 and 6. Interesting to know that.

What did you find out about yours?

 

[james.wetzstein]

Okay, here's an update: On the decent chance that the problem is refrigerant pressure, I bought a can of ACPro with the hose and gauge. The instructions specify turning on the AC at Max so as to have the compressor running while the refrigerant is added. My compressor wouldn't engage, so I called their tech support and they assured me that if all was well, I could just add refrigerant and once the minimum pressure was reached, the compressor would kick in. The problem was that without the compressor running, the pressure on the "low side" quickly went over the can's ability to actually add anything quickly, since the pressure on the low side quickly approached that of the can. After 30 minutes without any result I resigned myself to taking it into a shop.

Today, driving home with the windows partly open, I turned on the fan just to get a little more (un-chilled) air moving through the cabin. The AC kicked in automatically and CONTINUED TO RUN until I got home (thank you Jesus) where I was able to get the ACPro can connected. I was able to add a substantial amount of refrigerant and get the pressure within the recommended band.

So, my tentative recommendation is this:
If your AC light is flashing and you've ruled out the relay and your not getting any error codes, get on the DIY refrigerant (if you're comfortable taking that risk) while the problem of the compressor is still intermittent and you have a hope of having the compressor cycle on because once it stops, you're out of luck.

Having said this, I'm not a trained AC tech.

 

[earthrealm]

i have a similar problem, blibking ac light. its not freon or magnectic clutch.
the a/c trys to start, bogs down my rpm, and then fails to start, slight smell of hot rubber..and then the blinking light.

i think my compressor or magnetic clutch might be toast.

this happened to anybody before?

 

[earthrealm]

i have a similar problem, blibking ac light. its not freon or magnectic clutch.
the a/c trys to start, bogs down my rpm, and then fails to start, slight smell of hot rubber..and then the blinking light.

i think my compressor or magnetic clutch might be toast.

this happened to anybody before?

ended up replacing the compressor, it siezed due to low oil, i believe, as i had a leaking compressor seal ack then

 

[Syr4RinNC]

Hoping for some help

- a few months ago, the AC light started blinking and system wouldnt come on. I identified a bad mag clutch and had the compressor replaced by an auto shop earlier this week. They said they charged it up, but couldnt get power to it.
- I took it home, figuring, Id try to handle it if it was something easy (like the relay)
- A new mag clutch relay didnt help and using the fog light relay doesnt work
- The low pressure refrigerant reading is 40 PSI
- The system works if I bypass the relay in the fuse box with a paperclip (clutch engages and blows cold air).
- So I have a new compressor (denso OEM part), the refrigerant is filled to adequate pressure, and I can get power if i jump the relay. This seem be the major components
- I checked all the electrical connections to the compressor and the pressure switch and all seem fine.

Am I left with the thermister (AC evaporator temperature sensor) or the coupler that ties the compressor to the engine RPMs? Is there any easy way to test these without ripping apart the entire dashboard?

Any other thoughts or suggestions would be appreciated.

Edit:
If I disconnect the pressure switch, the AC light stays on, but blows warm air. If i reconnect, it blinks and nothing

I tried to pull engine codes and theres nothing