Flashing A/C Light (1 Viewer)

[Travis351]

FWIW, 7 years since my last post about the flashing AC light, I think its been 60,000 miles and mine still does it sometimes. Seems its only in the morning when I 1st start the rig, once I am moving I hit the button a few times and the AC starts, it won't do it again until the next day(or sometimes not)

I have not looked into it again, because its not a big deal to me, its just a quirk. front and rear AC blow very cold(no change in 60K) No codes.

but have done drive belt, T- stat, exhaust manifold, starter and alt(both lasted 160K) and a few other maintenance items in the last 60K.

I've replaced the relay, condenser, compressor, evaporator and drier and mine still does this from time to time as well. Getting moving and pushing the A/C button, once or twice brings it back to life. More in the dead of summer in traffic or situations where I'm idling more than usual. I've also noticed that the condenser fan is not spinning when I get the flashing light. I've been told to add an additional electric fan up there to help, but haven't done so yet.

 

[G-Cat]

For anyone conducting a search, this happened to me just after I hired-out the timing belt/water pump service. I didn't notice because it was December, in Kansas, and 2 degrees outside.

The tech forgot to reattach a piece of the AC harness he detached when doing the TB/WP.

 

[bulldogs93]

I recently started having this problem on my 01 LC as well, first thing I did was replace the relay which did not help, and Ive been told the code it is throwing is something about a solar sensor. Has anyone else had this code and know a fix?

 

[PADDO]

Code 21? Sensor not covered by something? You can pull the solar sensor and check its has infinite R when the photodiode is covered and drops to about 4K ohm under bright light. Pull the ACC fuse in the drivers footwell for >10 seconds to clear codes and see if that resets things.

 

[bulldogs93]

Thanks I tried that but didnt solve the problem. Ive fiddled around some and notice when pressing the A/C button while idling the rpms drop for a second like something is trying to catch and then doesn't, the light then starts to flash and the rpms return to normal.

Does this sound like it may be a timing belt issue?

 

[Travis351]

Doubtful on the timing belt. I would suspect the compressor or magnetic clutch. Does it ever run without flashing and work normally?

 

[bulldogs93]

Doubtful on the timing belt. I would suspect the compressor or magnetic clutch. Does it ever run without flashing and work normally?

No not since this problem began, I've tried turning it on and off while driving at normal speeds and it still proceeds to flash

 

[DirtDawg]

I also am thinking it might be the clutch or compressor.

 

[bigjay850]

Has anyone found out as why 2006 LX470 does not have MG CLT under the fuse box under the hood behind battery? See the pic.
Or is it in a different location?
My AC does this from time to time and R134a level is fine in the compressor. I've thought it was a bit low and after bit charging it (overcharging) it did not work, which makes sense. Then let some out back to norm and fine, but from time to time driving for longer periods it stops and does the A/C button flashing.
The only code from AC diagnostics is rear blower which should not matter especially when it's not in use and it actually works.

 

[Rahul]

Has anyone found out as why 2006 LX470 does not have MG CLT under the fuse box under the hood behind battery? See the pic.
Or is it in a different location?
My AC does this from time to time and R134a level is fine in the compressor. I've thought it was a bit low and after bit charging it (overcharging) it did not work, which makes sense. Then let some out back to norm and fine, but from time to time driving for longer periods it stops and does the A/C button flashing.
The only code from AC diagnostics is rear blower which should not matter especially when it's not in use and it actually works.

View attachment 1485515

Not sure if you still need the info, but if someone is looking for it , its C/OPN one (#90987-02022), you need to replace it by part#90987-02028. There seems to be a bulletin regarding the same ref AC light Blinking and AC not working.......... - ClubLexus - Lexus Forum Discussion

 

[Eliot]

I just had my A/C go out 2 days ago. Started the truck up after work with A/C on and I hear a loud screeching noise coming from the engine. No cold air and A/C light flashing.

Upon further inspection, it seems the clutch is attempting to engage but cannot and then the system recognizes the A/C shaft is not spinning with the driveshaft (as mentioned earlier in this thread) and therefore shuts off the compressor.

Pretty positive my compressor is locking up.

Is there anything else that could cause the system to lock up other than the compressor?

I'm very close to just ordering a compressor and replacing it. Assuming it's OEM, it's got 285k miles on it. What else should I replace when replacing the compressor? Do i really need to do the condenser? I plan to drive this truck for many years to come and am a proponent of doing things right and if I should rebuild the whole system I'll just go ahead and do it. Any advice is much appreciated.

Found Denso compressor for $280 at parts geek. Lexus stealership wants $150 to diagnose. I'm thinking might as well put that $150 towards new parts.

 

[Landpimp]

update from 2009

over the summer the flashing AC light got worse, this fall it was getting even worse, it would kick in after I was going down the road, but for the most part the AC light flashed whenever I got into the 100 and it took a bit to stay on(and the AC work)

its now been 3 weeks and I have not had to touch the AC button......it stays on all the time now!!......what did I do?......pushed in some electrical plug close to the AC compressor.....I don't think I even pushed it....more like a hard touch....there was no "click" of the tab from a unseated connector.....I really expected nothing. Now maybe I just got a break or something lucky but who know's. I have went back in my head and tried to recall any work that was done(back in 2009) that may have lead to the problem, it happened a year or more after the 1st timing belt and since then we have replaced alt, starter, driverside manifold.....it was doing it before and after that work.

It also seems the AC works different that it has since 2009, can;'t explain how but its different(in a good way) but it may just be my imagination.

so it may be worth it to go touch/reconnect et all the connections on the compressor and see if it helps..

 

[spaber05]

I'll chime in here as I'm now experiencing a flashing A/C light.

I first saw it driving down to CT from Boston, the light would come on solid for 2-3 second then flash. I thought I felt a little cold air for those few seconds but can't be sure. Fast forward to today, I take it into the local dealership that I trust, they say it's looking like the relay is bad and needs to be replaced, compressor looks good, no visible leaks in the system and the Freon is topped off. Trouble is, the relay is located under the junction block (what I call a fuse box) in the engine bay and apparently a pain to access.

They want $360 to access the relay but taking out the junction box, which does not including the cost of the relay itself.

Can anybody chime in on this? Is I true that the relay is so inaccessible?

Any help is much appreciated!

 

[spaber05]

Adding to the above, has anyone tried swapping the A/C clutch relay for the new part number listed above? Hoping it's that simple fix!

 

[vcheng]

I'll chime in here as I'm now experiencing a flashing A/C light.

I first saw it driving down to CT from Boston, the light would come on solid for 2-3 second then flash. I thought I felt a little cold air for those few seconds but can't be sure. Fast forward to today, I take it into the local dealership that I trust, they say it's looking like the relay is bad and needs to be replaced, compressor looks good, no visible leaks in the system and the Freon is topped off. Trouble is, the relay is located under the junction block (what I call a fuse box) in the engine bay and apparently a pain to access.

They want $360 to access the relay but taking out the junction box, which does not including the cost of the relay itself.

Can anybody chime in on this? Is I true that the relay is so inaccessible?

Any help is much appreciated!

Adding to the above, has anyone tried swapping the A/C clutch relay for the new part number listed above? Hoping it's that simple fix!

More info here:

2005 LX470 Main Junction Block Replacement

 

[spaber05]

More info here:

2005 LX470 Main Junction Block Replacement

Thanks, I'm hoping that's not the case with mine I was able to locate the relay and check to see if the P/N corresponded with the "faulty" ones found on previously mentioned sites. In my '06 LC the relay is labeled C/OPN and is definitely not permanently attached as in the link you sent me so fingers crossed.

Turns out I do have a relay ending in 2022 so I bought one ending in 2028 and we'll see if that does the trick. If not it's back to the drawing board.

 

[rickmb917]

I had the flashing light situation earlier this year. The original compressor went bad at 284k miles but the light didn't start flashing until compressor was replaced. Long story short, I took it to my usual mechanic (not a Toyota dealer) because the compressor was bad. He replaced it with a brand new non-oem compressor (twice). After both compressors, light would start flashing at idle (below 800 rpms) and ac would disengage. Toyota dealer replaced with an OEM unit and filled the fluids to the correct amount (non-oem called for too much apparently). Toyota dealer claims on the land cruiser, its computer system for the AC can be finicky if it senses the parts aren't to spec. Not sure if this is applicable for the situations herein but this is my story. Dilly dilly!

 

[spaber05]

I had the flashing light situation earlier this year. The original compressor went bad at 284k miles but the light didn't start flashing until compressor was replaced. Long story short, I took it to my usual mechanic (not a Toyota dealer) because the compressor was bad. He replaced it with a brand new non-oem compressor (twice). After both compressors, light would start flashing at idle (below 800 rpms) and ac would disengage. Toyota dealer replaced with an OEM unit and filled the fluids to the correct amount (non-oem called for too much apparently). Toyota dealer claims on the land cruiser, its computer system for the AC can be finicky if it senses the parts aren't to spec. Not sure if this is applicable for the situations herein but this is my story. Dilly dilly!

 

[spaber05]

Input appreciated! I'm hoping it's not the compressor as there have been no other symptoms before this but this might be helpful if the time does come. Here's to hoping that this $55 relay does the trick.

 

[vcheng]

Thanks, I'm hoping that's not the case with mine I was able to locate the relay and check to see if the P/N corresponded with the "faulty" ones found on previously mentioned sites. In my '06 LC the relay is labeled C/OPN and is definitely not permanently attached as in the link you sent me so fingers crossed.

Turns out I do have a relay ending in 2022 so I bought one ending in 2028 and we'll see if that does the trick. If not it's back to the drawing board.

Lucky that you have an 06. The 2005 is specially cursed in this regard. The AC is now working great after the main JB replacement, for me at least. Good luck with your relay replacement. BTW, has the drier cartridge ever been replaced? Just something to keep in mind when refilling with refrigerant to the correct specifications.