Have Toyota Questions? Ask a Mechanic for Answers ASAP
Good evening. If the A/C light is blinking on a Toyota, it means that there is a problem with the A/C system. The most common problem is the relay for the compressor.
Ok. Is the A/C compressor coming on at all or does the light go straight to blinking?
Ok. The A/C clutch is pulling more power than normal through the system. With the relay jumped with a wire you are eliminating the A/C switch circuit. The switch is what engages the relay to put power to the clutch. If the pressure switch was bad, the light wouldn't blink. The clutch would either cycle frequently or not at all. The only components in the system that can cause the light to blink is the Relay or the Clutch itself.
hi I'm a Toyota master tech may I shed some light on this problem?
hi again , yes read those notes. I have a different opinion on your problem, number one , yes the blinking A/C light does indicate an A/C problem and by jumping the relay you are eliminating the rest of the A/C circuit and that's what we do to check to see if the clutch and compressor are working.so you made it a little easier for me to narrow it down for you.If the compressor was pulling to much power it would blow the circuit breaker but it's not and the A/C actually works right? so the next thing is this the drive belt is in good shape and not slipping right? make sure the charge pressures are right not over charged with Freon, especially on the high side when operating, this is important because if the pressure switch senses too high of pressure it tells the amplifier that and it starts to cycle too often, next if all that is correct the belt and pressures check out to spec then replace the RPM sensor located on the compressor making sure the wiring and connectors are in good shape. If this RPM sensor is faulty it also sends a wrong signal to the amplifier to cause it to cycle and not work properly. hope this helps and gives you a better idea how your A/C system works. good luck and let me know.
hello again it;s Peter, yes my answer is totally different but I have been a Toyota tech since 77 and am a Master tech so I bin around for awhile, and when I saw him tell you it's the compressor I THOUGHT BEFORE YOU SPENT THAT KIND OF MONEY ON A COMPRESSOR i'D JUMP IN TO TRY AND HELP. iF IT WASTHE COMPRESSOR WHEN YOU JUMPED THE RELAY AND MADE IT WORK IT WOULD HAVE BLOWN THE HIGH AMP FUSE LINK WHICH IT DIDN'T DID IT? LIKE YOU SAID IT RAN AND COOLED THINGS DOWN. WELL LIKE i SAID WE DO THAT TOO TO ISOLATE THE COMPRESSOR FROM THE ELECTRICAL PART. NOW YOU HAVE TESTED THE REST -- PRESSURES ETC THAT LEAVES ONLY TWO ITEMS THAT CAN CAUSE THE PROBLEM YOU DESCRIBE. AND COMING ON AND OFF THAT FAST WITH LIGHT BLINKING BEST DESCRIBES THE RPM sensor or AMPLIFIER to be at fault and being that the RPM sensor is easier and cheaper to replace and try I would suggest to go there first. the RPM sensor depending on the part number of your compressor should be either on the lower front side , or the end of the compressor, as for where you can get one I don't know if after market parts carries them you may have to go to a dealer they can also show you where yours is located with your vehicle's vin number. As for cycling that is when the compressor turns on and off it's just now yous is double timing with a blinking light so the Amplifier is getting a wrong message and that only comes from one of two sources, the pressure sensor or the RPM sensor. to replace the amplifier is an expensive and time consuming job so that's why I'm recommending replacing the RPM sensor it is most common to do too. I totally understand your concern about conflicting ideas but even doctors and lawyers can sometimes agree to dissagree but hopefully come out with the same resolve to fix the problem. I hope this helps and please let me know if I can be of more help. good luck.
To simply answer that if it were a clutch it wouldn't have engaged when you jumped the relay and most RPM sensors can be replace without evacuating the system but like I said check the model or part number first just to be safe. good luck
well some parts are known by different names from different t areas or shops, we call it an RPM sensor because that's what it does, it senses the compressor turning and sends that signal to the amplifier which matches it to the engine rpm, if it don't then you end up with the problem your experiencing. as for you trying to compare the problem you had with a sienna and this one , if you would have jumped the relay on the sienna it would show you the compressor clutch wasn't working right away but when you jumped the relay in this vehicle it did intact work right? you can go ahead and replace the compressor and if you get a used one it may work for you because it will come with a different sensor that is working and may be a cheaper alternative, but then you need to evacuate the system and recharge it. check this link out https://www.google.ca/search?q=1996+camry+a/c+speed+sensor&tbm=isch&tbo=u&source=univ&sa=X&ved=0ahUKEwjR8LH4p67OAhVEKCYKHRMoBQkQsAQIPg&biw=1920&bih=955 like I pointed out you already confirmed the clutch and compressor works by jumping the relay and you tried the relay .look I've bin in the trade over 45 years and with Toyota since 76 and that's my gut feeling given the info you provided . like I suggested throw a used compressor assembly on it and recharge it and call it a day if that's the way you want to go, it may be cheaper then just the new sensor.good luck
Just checking in to see how your doing and what you have done so far.
that would be the smarter move is to get a used sensor or complete compressor what ever is easier for you . , I know that link was a little miss leading but just wanted to show you that there is such a thing as a A/C compressor speed sensor lol, it's job is to match the engine rpm to that of the compressor signal to send to the amplifier and then the amplifier can do it's job. hope this helps and hold off on that extra $15 until you tried a different sensor OK. good luck.
well between the amplifier and speed sensor it's by far the most common part failure , now that's assuming all those other things I mentioned before check out properly those are the only two left that can cause it.
Before we skype and charge more try that speed sensor and check it's connections first. good day.
just checking your progress and if you tried that speed sensor compressor yet?
very well and good luck , if you need any more assistance let me know , happy to help.
Hi Dean not knowing how much you lost , Here is the oil capasity for the system mineral oil for R12 Freon 8.75 ounces. If it has been retro fitted with R34 refriferent then you needto use the proper oil.
My apologies , I assumed that you were aware that removing the speed sensor would do that, forgive me for assuming that, but either way if you got a complete used compressor or just the sensor you still needed to e vac the system before charging because when the system is open to the air it draws in moisture which can cause internal freeze up and troubles.when you just top it up you don't need to because your not allowing moisture into the system. Also without a vacuum you won't get a complete charge even though the Gauge may show good pressure it still may not have enough refrigerant in the system., you can try it but be forewarned. Also you can lubricate the sensor seal with a little of the compressor oil that save s any contamination getting into the system. If you can estimate how much oil came out you may not need the whole amount as i stated that's from empty. Again my apologies , some times just texting procedures on here I get ahead of myself.
mmm they are actually high on both sides but way off charts on pressure side.has any one topped the system up recently?perhaps over charged. the pressures should be low side--25-35psi high side - 175-185
This is a different car and question so I will require additional time, thank you.
Well this is not only a different question but different car so yes and we can take it as far as the other one if you agree.
well if you look back at the pressures what you gave me your high side is excessive and low side below normal as to the ones for that vehicle, that indicates a blockage at the expansion valve . if it were equal on both sides it would be an internal leak in the compressor and that's not what your experiencing. and it is putting out good pressure even though high so the compressor is working.so that my friend leaves just one thing, the expansion valve. advise you to replace it soon because it can cause damage to the compressor. You can try an A/C flush if you have a shop that is capable of doing that and it's just clogged but that's up to you.
thank you and glad your happy.