A/C Light Blinking Troubleshooting Guide

Have a 2010 and did all the great ideas from all the postings. Light was flashing. The clutch would engage and then disengage. Since it was engaging was leading me down a different path. I finally realized when clutch engaged the center portion of clutch was not spinning. The center portion is the compressor. Compressor was not seized and spun freely. Realized clutch is similar to a harmonic balancer, inner and outer attached by rubber. The rubber separated and prevented compressor from spinning. When comp does not spin, sensor does not see it turning and cuts out the clutch. Replaced clutch, very simple one bolt, installed original spacers and A/C working perfect, very cheap repair. Thanks for all the great post, all very helpful.

 

So I've had an AC problem for over a year. I've replaced a majority of the parts but still have intermittent AC. Probably the most frustrating issue I've had with any vehicle I owned and I cannot figure it out for the life of me.

I've replaced:
Compressor
Compressor pick up sensor
EVAP thermister
Mg clutch relay
Associated fuses
Ac amplifier assembly
Pulleys and belt

Light still blinks every 10-15 minutes. R134a @ 90* 36psi/200psi. Not too sure what to do next lol

 

have you inspected all the wiring?
https://www.tacomaworld.com/threads...bleshooting-guide.440200/page-2#post-20577743

 

Did any of you experience a popping sound then smell rubber burning. My a/c light started blinking and no cold air. 2006 Tacoma

 

Did it require removal of the belt? Or just take off that small bolt?

 

We have seen multiple issues with flashing A/C lights here at Lexus. There is an updated relay.

If you do change out the relay, be sure it's the newer part number.

 

Did you ever figure it out? I don't really have a while, but the RPM piece is on point... Mine intermittently goes in and out, frustrating as hell.

 

Wanted to add my experience. This single thread alone helped me solve my issue and probably saved me a ton of money this week.

2015 DCSB 6sp manual 4.0L (@ 120,000 miles)
-still using original compressor, belt less than 5,000 miles on it

First issue came up like everyone else, I had a blinking "A/C" light. The blower worked fine at all times. But it would lose the cold air after 10-15 minutes of driving around town and the light would begin blinking. No odd smells for me. My plan was to start small. First just make sure compressor is engaging, get a buddy to throw the AC switch and make sure you see it engage/spin in engine bay. Then a quick re-charge A/C can, no luck. Next tried the relay under the hood/fuse box. No luck. **At this point your $20-$30 in?

Next was the sensor. Sensor is about $100, located on the bottom of the A/C held on by a single small bolt (10mm head). I did not have to remove any other parts, but it was a pain getting your hands in there. I think it'd be easy if you remove the skid. I got lazy and didn't want to remove everything. Remove the skid and get up there. You can actually see it at full driver wheel lock and taking a flash light up there. I shoved a flat head into the clip side of the wire harness to lift the "clip" and just gently pulled it off while leaving the flat head slightly wedged in there.

The old sensor looked visually fine after I removed it. I did not test it on a meter sense I already had the new part. Nothing about the original sensor screamed broken. But sure enough, changing it out fixed the issue. It's been one week so far and no issues.

I hope that helps some future projects, big thanks to OP for the info!

Part number used "88346-04010" > sensor

 

Hello all! Bumping this thread and hoping for a little help. 2014 TRD OR. Having the blinking light issue. Used to blow some cold air and then blink, but for about the last 6-8 weeks it just immediately and always start blinking and blowing warm air. I've replaced the Mag Clutch Relay and the Compressor Pickup Sensor. My next route will be checking the grounds on the compressor and the pressures. For the grounds, any help as to where to look would be helpful as it's such a pain to see anything in that location. Also, with pressures, can I just use a freon recharge kit or is there something more technical I need? Thank you! Trying as best i can to avoid a professional, but AC diagnosis is not my forte.

 

First post on the forum although have browsed for some time now.
I found this thread particularly interesting as this past summer I experienced the same issues many apparently did, AC light blinking followed by warm air blowing from the vents, et.
My dealership where I purchased the Tacoma new in 2005 diagnosed the problem as being an internal bearing locking up in the compressor.
The compressor was replaced and the system recharged resulting in cold air now flowing from the vents.

However......30 miles down the road to home the AC Light began flashing again accompanied by warm air again blowing thru the vents, so the Tacoma was immediately returned to the dealership, a lease vehicle was furnished so further testing could take place.

Got a call two days later saying that the system had been recharged, tested, and left to set overnight.
12 hours later it was found that coolant had leaked somewhere in the system resulting in the same flashing light/warm air discharge from the vents as before.
After a further, more detailed evaluation it was discovered that a replacement seal at the compressor had a very small, nearly undetectable, pin sized hole in it allowing some refrigerant to escape, enough to trigger the light again..

The tech removed and replaced the replacement seal, part number MT2583, recharged with the proper amount of refrigerant and no further issues after almost 6 months now.

The dealership found that the replacement seal leak had evidently been an ongoing problem for quite some time, advised to order 1000 immediately because stock was running low and backordering would be inevitable soon. My dealership in Mid Michigan ordered and received 2,000, so apparently the seals had, and have become a major issue, only recently discovered.

Just a heads up, it may indeed help someone else or at the very least, provide a starting point for others with AC flashing light/warm airflow, issues.

 

Good info!

 

Im curious if the light is consistant? My light comes on like described but on consistently? Dealer told me to monitor till it come more obvious. The system was replaced 2 years ago. Comprssor, evap core, dryer, etc. They said compressor shrapnel was found everywhere and no flush out kit available. Was under warranty so let them do whatever.

 

Yeah I'm going that direction first thanks

 

Thanks OP…just went through this and ended up being the Compressor Pickup Sensor

 

Hello to all and Thank You in advance! I have a 2012 tacoma and have been dealing with the ac blinking light nightmare for 4 years now. First time was in 2017. I had an extended warranty so I took it to local dealership. They said they found metal in the system and would need to replace the entire ac system. I wasn't paying for it so I was fine with it. To make an extremely long story short, since then they have replace the ac system 7 times over the last 4 years. Every time they claim to find metal in the system and claim to replace all ac components. It varies on how long each fix will last. My service writer says they blame it on faulty compressors. He says he has 5 or 6 other trucks like mine with the same issue. They have blamed it on where I live, saying it gets to hot! Last time I picked it up in January of this year, it was the dead of winter. I would use defroster only on my way to work. 2000 miles later it did it again! It's going back in on Wed. For the same $4000+ change out of ac components. This is the most frustrating thing I've ever experienced. Just doesn't make sense. Thank you again for reading and any and all comments or advice is welcome!

 

I understand what the diagram says to test but how do you go about testing at home? How do you attach the tiny leads to a battery?

 

I used some very small female spade connectors like these.

20pcs 10-12 AWG Insulated Female Spade Wire Crimp Terminal Connector Yellow

https://www.amazon.com/Insulated-Female-Terminal-Connector-Yellow/dp/B01M4QSWSM I forget exactly what size they were. I crimped wires to them to reach the battery, and put electrical tape on the metal part to try and avoid any kind of short. A fuse wouldn’t be a bad idea on the positive lead.

 

Thank you for the quick answer.

 

How to check the clutch was normally ?
I try to turn the clutch by hand when the car is off, and it's can turn, is this normal?