Hey folks,

I'm not too familiar with Car AC diagnostic and wondering if y'all can steer me in the right direction.

Description of problem: AC does not blow cold air on either side, no actuator fault and no faults pertaining to the AC at all (or any other fault for that matter) using the onboard diagnostics. The AC button does not blink or turn off, which would indicate low on freon (from what I've read). The AC was strong one day and did not work at all the next. The AC Control reads ambient temperature correctly, and works flawlessly otherwise. I did take it apart to re-solder the connections for a brighter display some months ago and had no issues with functionality.

I have checked all related fuses, no issues. I have swapped the Horn relay with AC relay to verify no issue there. The clutch on the AC Compressor is sitting about 1/2 inch off the face of the pulley with the AC clicked on or off.

My best indication is that the AC compressor has gone bad? I have not seen the clutch sitting off the face like mine is (I will get a picture later today) but I am also unfamiliar with Car AC systems.

Living in Florida, I definitely need AC. I will get refrigerant levels checked prior to anything further but was wondering if anyone had an inkling.

Thank you!

 

If you are not going to do the troubleshooting and repairs, telling you the possibilites does not help much. Take it to a trusted shop.

 

Are you just looking for what it may be or do you want to try to diagnose it ??…if you live in Southwest Florida bring the car by.

 

I have done troubleshooting so not sure I understand your response. I can go as far as hooking gauges up and checking pressures if I need to.

Tampa area, what shop are you with?

 

If your compressor clutch surface is 0.5” away from the pulley face, it will not engage. The correct gap between the clutch and the pulley is about 0.040”.

when you press the a/c request button and the light comes on, is the compressor clutch engaging with the pulley and turning the compressor shaft?

 

Ok. That's the quickest way to assess your refrigerant charge. Are you saying that was part of your troubleshooting?

 

I am my own shop…do you have a 12 volt test light and can make your own jumper wire for the clutch relay ??

 

The clutch is not engaging with the AC on (light on) and the clutch does not change position. What could cause the clutch to be doing this?

Yes sir.

 

OK, first let’s check fuse 24 with a test light KEY ON…test light should illuminate on both test points…next remove relay 34 and with KEY ON test light should illuminate on terminals 30 and 86…they are control and load side feed and are closest to the engine…arrow in drawing is forward…in both terminals light jump 30 and 87…you should hear the clutch “click”…if you hear that the clutch is working but we still don’t know if we have “control” but we can worry about that later…now there are some inputs that the PCM must see before it “grounds” the control side…ambient temp, high side pressure…these inputs are best seen with a scan tool as well as “AC Request”…when you press the AC button the scan tool will show a YES…if you can get your hands on an AC manifold set you can see if you have at least enough static pressure with the engine off to see if you have enough pressure to engage the clutch…we use ambient temp as a guide…if it’s 80 degrees out and the static pressure is 80 psi the clutch should engage…also @bookyoh is our resident expert…we can start there.

 

[QUOTE=alex04vette;1608413346]The clutch is not engaging with the AC on (light on) and the clutch does not change position. What could cause the clutch to be doing this?

Please take a photo from the side to show the air gap between the compressor clutch and pulley and a photo from the front looking at the compressor clutch.

 

I'll come back with the test light jump later today. I don't think the grounds have ever been cleaned on this car and it does look like it lived within ocean breeze distance for some of it's life because the corrosion is not what I'd expect.





and yes, that steering rack hose clamp does look broken and I did not notice until now lol

 

I would only concentrate on the compressor circuit ground for now…G102 is the ground but there is SP (Splice Pack) 100 where a few ground wires are connected before they go to that body ground.

 

You have a mechanical issue that needs to be fixed first. That is not an OEM compressor and some mechanical failure has allowed the clutch to or pulley to move away from each other. You an try to rotate the crutch by hand and feel if it is seized or free wheeling. Perhaps this aftermarket manufacturer uses a slip fit of the clutch hub over the shaft, rather that the press fit used by OEM.

Here is what an OEM compressor looks like.

 

I took it to a local shop that specializes with vettes. They confirmed aftermarket AC compressor and the spring was completely gone for the clutch to engage.

Got it replaced, recharged and good to go. It's working great.