AC Button Indicator Blinking

[Paulie]

Hi All,

 

I'm wondering if anyone knows why the AC indicator light might have started blinking?

I've recently replaced the HVAC control unit for a spare while my original is having an LED upgrade.  I didn't realise that the AC indicator light was blinking earlier because it was an unusually sunny and dry day here in Wales.  But when I just went out in the car, I noticed it was blinking.

I'm just wondering if this is a possible issue with the HVAC unit, or could it be something else.  If it's the HVAC unit, I'll just wait for mine to come back from being LED'd.  If it's something else, it may well be another trip over to Mr Whiffin.

 

Cheers,

 

Paul

[rider]

"

Toyota AC light flashing

If you have a Toyota AC light flashing condition, the problem may not be as bad as you think. Toyota AC compressor clutches use a lock sensor circuit to make sure the clutch is fully locked-up to the compressor when the AC is on. The lock sensor generates an AC voltage as the clutch turns and sends that signal to either an A/C amplifier or ECM (depending on the car model). The signal is compared to engine RPM and that’s how the system knows that the AC clutch is slipping.

Diagnose Toyota AC light flashing

So the first question you have to solve is what’s causing the AC clutch to slip. The first thing to check is the belt tension. Check to see if your engine is equipped with an automatic serpentine belt tensioner. If so, read this article on how to check the condition of a belt tensioner. If your engine has a manual tensioning device, check the tension by pulling up and down on the belt to gauge belt deflection. If it’s more than 1/2″ it’s too loose.

Next, check for poly-rib belt wear using a belt wear tool. You CANNOT gauge poly-rib belt wear visually. Read this post on how to measure poly-rib belt wear. Trust me on this.

If the belt is properly tensioned and in good condition, you’re next step is to check the AC clutch

Why is my Toyota AC light flashing

The AC clutch works with an electro-magnet. The AC clutch coil can burn out, short out or sometimes even become too weak to engage properly. However, those same symptoms can appear if you have a pitted AC clutch relay. So your first step is to use a jumper cable to provide battery power and ground directly from the battery. Hotwire the AC clutch and start the engine. If the Toyota AC light flashing condition disappears, replace the AC clutch relay. If the AC light flashes, make sure the magnetic pickup inside the compressor is still in place. Sometimes they can fall out.

If you still have the Toyota AC light flashing condition, replace the sensor"

[Paulie]

Hi Rider,

Thanks for that.  Very comprehensive indeed.  Having little knowledge of how to do much of that I think the Supra may have to take another trip to Mr Whiffin.

I'm hoping that the compressor isn’t about to seize, this will be the second new compressor to seize so I’m thinking there could be an underlying issue that needs addressing.

Cheers,

 

Paul