2007 Tacoma A/C Blinking Light

Yea that capture was taken with a Picoscope 4425 which is pretty high end.

So with the relay installed the clutch does not engage and you have a flashing light?

Need to put some service gauges on it and see what the pressures are doing.
There is a pressure switch but it wouldn't make the light flash, the light only flashes when the A/C Amplifier commands the MG CLT Relay on and doesn't see the correct signal from the Lock Sensor.

 

Very nice!

That is correct, I do hear it click though. Maybe it's worth throwing a brand new relay at it, I've only tried switching the horn relay in, with the same result, but I think you mentioned in a post the MG CLT relay is the only one that is diode suppressed?

Hmm ok, I don't have access to gauges and can't perform mechanical work where it's sitting atm.. basically just trying to troubleshoot as much as I can to hopefully then order parts and have my mechanic install them. Feel like I'm getting closer though!

 

Interesting that the relay clicks but the clutch doesn't engage but you can engage it by jumping out the relay, that suggests a bad or incorrect relay.

I mean if the compressor is running but it's not cooling you really need gauges to diagnose it.

 

Having the same issue were u guys able to fix the issue

 

Have a question for you. I started having an AC issue. I bought a truck and the AC blew warm. I put a can of freon in it and it worked great for about 3 weeks.

Now yesterday I started the truck had a loud noise that I have no doubt was the AC clutch. The noise stopped when I turned ac off and now I can’t replicate the sound.

my main question is this. When I start the truck and press the AC button the clutch engages when I turn the ac button off the clutch stops like normal. However I still only have warm air, and the light on the AC intermittently blinks.

how can I tell if it’s just the AC clutch that’s the issue or know if it’s the whole compressor?

 

I'm no expert, but what I found is that you can see if the clutch is working or not by observing the inside part of the pulley (post #33 from Dm93 has a good picture), shine a light on it to really see. When it's connecting the compressor to the pulley, the inner part of the pulley will spin (circled in red in the picture). You'll also hear it click as it engages or disengages.

In my case by manually triggering it, I could get it to spin, but I still have no cold air, so there may be a compressor problem or incorrect refrigerant pressure (from what I understand). In all cases, the outer part of the pulley should be spinning with the belt evidently

 

Okay that makes sense I see what you are saying.

let me ask you this. Say the outter ring is spinning, the inner ring is not spinning consistently. Would that mean clutch or compressor?

I know the outter ring is spinning, and I can’t replicate the noise but didn’t check the inner ring I didn’t know that was a thing.

 

If the inner ring isn't spinning at the same speed as the outer ring, I would assume the clutch is slipping. Does this mean it's a clutch problem? I'm not sure TBH, if the compressor is compromised and hard to turn, maybe the clutch would slip. However they are designed to be on/off as far as I know.

The electronics (lock sensor on the compressor + AC amplifier which controls everything) are there to detect such issues and disengage the clutch if there's any speed difference, to prevent the pulley (outer ring) from wearing or shredding the belt.

One thing that I would like to see is a logic chart for the A/C amplifier, I'm guessing that exists, to be able to see the control sequence once the A/C button is pushed