Trunk Monkey
Moderator
Friend of mine is and he's on Mud, I've pointed him this way.
Flashing A/C Light
- Thread starter campoj2
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Friend of mine is and he's on Mud, I've pointed him this way.
- Thread starter
- #22
THANKS!!!!!!!!
Hi,
I'm not a Toyota Tech, but I have an idea as to what may be happening. I believe that compressor has a speed sensor, which will shut down the system and flash the A/C light, if it senses that the engine rpm and the compressor rpm are out of the range that Toyota has determined are acceptable. I think the idea is that if the compressor is locking up, by shutting down the system, the belt will remain intact and the vehicle remains driveable. Toyota has been using this system for years. I have seen worn drive belts create this problem if the belt slips on the A/C pulley. The speed sensor could also be faulty also. I'm certain that there are other things that will create this problem and I'll let others more qualified than I, chime in.
FYI, we sell OE Denso parts, the new compressor w/clutch is $378.49, the dessicant kit runs $20.75, the condenser is $371.62 and the expansion block is $46.49. This will at least give you something to compare to.
Good luck,
Rex
CoolStream
I'm not a Toyota Tech, but I have an idea as to what may be happening. I believe that compressor has a speed sensor, which will shut down the system and flash the A/C light, if it senses that the engine rpm and the compressor rpm are out of the range that Toyota has determined are acceptable. I think the idea is that if the compressor is locking up, by shutting down the system, the belt will remain intact and the vehicle remains driveable. Toyota has been using this system for years. I have seen worn drive belts create this problem if the belt slips on the A/C pulley. The speed sensor could also be faulty also. I'm certain that there are other things that will create this problem and I'll let others more qualified than I, chime in.
FYI, we sell OE Denso parts, the new compressor w/clutch is $378.49, the dessicant kit runs $20.75, the condenser is $371.62 and the expansion block is $46.49. This will at least give you something to compare to.
Good luck,
Rex
CoolStream
- Thread starter
- #24
Hmmmmm, Speed Sensor - is that easy to put in or do they have to remove the entire compressor to get to it?
I got a price of $472 for the compressor w/clutch
What is a dessicant kit?
John
I got a price of $472 for the compressor w/clutch
What is a dessicant kit?
John
Hi John,
The dessicant kit replaces the receiver/drier that was commonly used on earlier vehicles.(pic #1) It is now part of the condenser, the cylinder(see pic #2) on the side has a large nut on the bottom, thru which you can replace the bag. The speed sensor is usually on the back-side of the compressor-you can get an idea from the picture if you follow the wires around.(pic #3) I think if you have access to the back-changing it is simple.
The dessicant kit replaces the receiver/drier that was commonly used on earlier vehicles.(pic #1) It is now part of the condenser, the cylinder(see pic #2) on the side has a large nut on the bottom, thru which you can replace the bag. The speed sensor is usually on the back-side of the compressor-you can get an idea from the picture if you follow the wires around.(pic #3) I think if you have access to the back-changing it is simple.
- Thread starter
- #26
I was looking for the dryer and could not find it, I thought they changed the name to evaporator - you should see the price on the piece of equipment! $21.00 for the dryer is something affordable.
I am at the point of just replacing the whole compressor - and I am hoping that fixes the problem. The main reason why I am hesitating is the fact that no one seems to know what the code is that the truck is throwing (Rear Defrost & Rear A/C). I do not want to replace something that does not need to be replaced and in the end it does not fix the problem.
Once we can figure out the codes then we can formulate a plan and then we can fix the problem.
John
I am at the point of just replacing the whole compressor - and I am hoping that fixes the problem. The main reason why I am hesitating is the fact that no one seems to know what the code is that the truck is throwing (Rear Defrost & Rear A/C). I do not want to replace something that does not need to be replaced and in the end it does not fix the problem.
Once we can figure out the codes then we can formulate a plan and then we can fix the problem.
John
Trunk Monkey sent me over here. What 1972FJ55 said is exactly right; anytime the A/C computer (referred to as A/C amplifier in Toyota literature) turns on the magnetic clutch to engage the compressor, it monitors engine speed and a/c compressor shaft speed. Typically the pulley on the compressor and pulley on the engine crankshaft are the same diameter, so the A/C amplifier wants to see the same speed for the engine RPM and A/C compressor RPM. This is a safety feature to prevent any damage from being done to the serpentine belt in the event the A/C compressor actually locks up. Keep in mind anything that could prevent the A/C compressor magnetic clutch from engaging, or prevent the A/C compressor from turning at the same RPM as the engine could cause the A/C light to flash. This could include any circuit or control problem in the magnetic clutch, magnetic clutch malfunctions (including incorrect clearance), loose/stretched belt, bad A/C compressor shaft speed sensor or wiring, or a faulty compressor that is actually locking up.
Although, it could be a faulty compressor, the symptoms you describe don't sound like it. Typically when the compressor is actually locking up you would hear all kinds of horrible noises, and its doubtful that any cool air would come out the vents. Any chance that you have had any repairs done lately that could have caused this, a timing belt replacement for instance?
Although, it could be a faulty compressor, the symptoms you describe don't sound like it. Typically when the compressor is actually locking up you would hear all kinds of horrible noises, and its doubtful that any cool air would come out the vents. Any chance that you have had any repairs done lately that could have caused this, a timing belt replacement for instance?
- Thread starter
- #28
The PO supposedly had the T-belt replaced before he sold it to me, but when I asked him for the receipts from the dealership he does not respond to my email.
The compressor does not appear to make any noises - however, my mechanic was telling me that after he activated the A/C switch numerous times he could smell something in the vents -burning type of smell. Could this be the clutch and if so, what codes should be thrown by system?
I had the serpentine belt replaced in January, along with a TRD specific thermostat. This service was completed at the dealership in Montgomery AL.
I think that this problem is heading for the dealership - I wish I knew what the codes meant so I at least could estimate the damages to my wallet and prepare for the hit. I would also know what the service tech is telling me is spot on or a dog and pony show.
The compressor does not appear to make any noises - however, my mechanic was telling me that after he activated the A/C switch numerous times he could smell something in the vents -burning type of smell. Could this be the clutch and if so, what codes should be thrown by system?
I had the serpentine belt replaced in January, along with a TRD specific thermostat. This service was completed at the dealership in Montgomery AL.
I think that this problem is heading for the dealership - I wish I knew what the codes meant so I at least could estimate the damages to my wallet and prepare for the hit. I would also know what the service tech is telling me is spot on or a dog and pony show.
I would give the engine bay a good look over just to make sure nothing looks like its out of place or unplugged; pay special attention to the connectors and wiring near the A/C compressor as its easy to get out of place while changing the timing belt and it could be the root cause of some of your issues. Probably worth grabbing the magnetic clutch on the front of the A/C compressor as well and see if it has excessive free play, it should be pretty tight; you could even watch it while its running and make sure its rotating properly.
The code that is being displayed, "Rear Defrost light" indicates normal system operation. The A/C system does not monitor any part of the magnetic clutch system/circuit for abnormal operation.
The code that is being displayed, "Rear Defrost light" indicates normal system operation. The A/C system does not monitor any part of the magnetic clutch system/circuit for abnormal operation.
- Thread starter
- #30
Ol' Girl is going to the Stealership tomorrow am. Standby for more on this one.
- Thread starter
- #31
Went to the Stealership today and got some news:
They said that the compressor is fried
Quoted me $1900.00 to repair the A/C with 8 hours of labor- That's not a typo
I found a nippondenso reman w/clutch and drier at a-air, next day air to my house for $365 (sold)
I go outside to my rig after work and turn on the A/C and the light IS NOT flashing - blowing warm air
I wonder if the compressor is actually fried, the system was pressure checked and it had adequate pressure.
They said that the compressor is fried
Quoted me $1900.00 to repair the A/C with 8 hours of labor- That's not a typo
I found a nippondenso reman w/clutch and drier at a-air, next day air to my house for $365 (sold)
I go outside to my rig after work and turn on the A/C and the light IS NOT flashing - blowing warm air
I wonder if the compressor is actually fried, the system was pressure checked and it had adequate pressure.
- Thread starter
- #32
Pulled the compressor today and it was locked up, the new one is being installed this afternoon and I should be making ice cubes by happy hour 
I have an 03 4runner with the 4.7 IForce V8 and I had the same problem. The relay you need is labled MG CLT or somthing close. It should be the same as your DOME relay. I swapped those two relays and my DOME did not work but my A/C compressor did, that let me know that the relay was bad. I took the relay into my workshop to dissassemble it but found it was sealed so I dropprd it a few times from about 6 feet so it would land on the flat top side, the installed it back into its original pasition, and it worked! This is not scientific but it got my A/C back on till I can get a new relay. I have read that the 90987-02022 needs to be replaced with a 90987-02028. Advance Auto has a replacement for 41.49. Stock # R6034. Let me know if this helps anyone out there.
- Thread starter
- #34
I bought the relay (now I have 2) and it was not the problem, I do have an extra relay downstairs if you want it, I won't charge you what they charged me. If you want it send me a PM.
bluecruiser
SILVER Star
I had my A/C light flash yesterday. The air became really humid and I looked down and saw the light flashing.
I was driving through a lot of water, not deep, but constant splashing for a mile or more when this happened (shallow river in the area).
Could it be that my belts slipped because of the water, giving me the flashing light? I turned off my A/C for about 5 minutes and when I turned it back on, it was fine.
Has not flashed at all since.
I was driving through a lot of water, not deep, but constant splashing for a mile or more when this happened (shallow river in the area).
Could it be that my belts slipped because of the water, giving me the flashing light? I turned off my A/C for about 5 minutes and when I turned it back on, it was fine.
Has not flashed at all since.
Old thread but this issue just popped up on my 99 100 with 182k. I bought it with close to 179k a few months ago. A/C was working perfectly. Looks like the first thing I'll try is the MG CLT..?...
I've been experiencing the flashing AC light lately. Have been able to get it to run by turning the AC off by pressing that button and turning it back on. Sometimes more than once is needed. Seems like if I do it while the AC is moving once is enough. Anyone find any diagnosis or solutions not mentioned in this thread?
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 maintence items in the last 60K.
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 maintence items in the last 60K.
As another poster noted, check your connections to the compressor. I was having the same issue. I replaced the MG CLT relay and was still blinking. I went thru the connections and pushed tighter and eureka, blinking light stopped and cool air blowing!
