A/C Went Out

[vettn71]

1990. It cycled cold, then hot a few times, then just quit. Any likely suspects?

Jim

[GOLDCYLON]

If you have automatic AC controls is the Green LED flashing

Did you lose the fan? Or just not blowing cold with a flashing LED

[vettn71]

Darryl

Fans fine. Green light does not blink, but I thought I got a wiff of something frying

Jim

[GOLDCYLON]

Darryl

Fans fine. Green light does not blink, but I thought I got a wiff of something frying

Jim


Hmm well a flashing green light points to a Freon leak. Maybe a possible AC fan clutch failure. Do you see the compressor engage when on?



Blower is working so blower fan and blower Controller seem to be ok as do the ac controls.

Take a look at the compressor

[vettn71]

I could feel the compressor cycle when I was driving it, but I guess that doesn't mean it's okay

Jim

[GOLDCYLON]

I could feel the compressor cycle when I was driving it, but I guess that doesn't mean it's okay

Jim


Im wondering if its seizing. Take a look at idle

[Kevin]

happened to me last year, compressor is locked on mie

[cvette98pacecar]

That :censored:.

[vettn71]

Not what I wanted hear, but it is what it is. My wife is gonna unwind when I pay that bill! Thanks for the input, y'all

Jim

[Schrade]

Put a guage on the fill fitting. Even a Mickey Mouse InterDynamics guage will give RELATIVE numbers, if not exact, with the compressor off, and then cycling to on...

[-=Jeff=-]

If the clutch is bad you can fix it without pulling the compressor
I heard it is mainly the clutch that goes

[Racinfan83]

I actually just changed the clutch on the A/C compressor on my truck yesterday. The magnetic coil that engages the clutch was bad. Works like a champ now!
Check to see if you have power to the clutch with motor running and A/C on. If you have power to there - then either the compressor is locked or clutch is bad. You can shut the motor off, remove the belt, and push the clutch plate in to see if you can turn the compressor over by hand. If so, and you have power to the clutch - then good chance all you need is a clutch assembly. You mentioned a burning smell - that could be caused by a locked up compressor and the clutch burnt itself up - so make sure the compressor itself turns...
I paid $83 on E-Bay for the one for my truck and changed it in about an hour without removing the compressor or losing any refrigerant.
Keep in mind this was on my DODGE TRUCK - but I would think the procedure would be much the same...

[scottfab]

Wow you guys are good. Covered the whole thing in less than 24hrs.
I can't add a thing other than when my compressor went I converted from R-12 to R-134a.
All it took along with a new compressor was a new dryer and orifice.
Loaded it with the R-134a friendly oil and then charged her up with R-134a. Works like a champ. That was over 10yrs ago.

[GOLDCYLON]

Wow you guys are good. Covered the whole thing in less than 24hrs.
I can't add a thing other than when my compressor went I converted from R-12 to R-134a.
All it took along with a new compressor was a new dryer and orifice.
Loaded it with the R-134a friendly oil and then charged her up with R-134a. Works like a champ. That was over 10yrs ago.


True enough. Most of us have been there done that as our cars are getting a little long in the tooth.

[vettn71]

Odd thing. Worked this morning like brand new. .???

Jim

[GOLDCYLON]

Odd thing. Worked this morning like brand new. .???

Jim


Hmm electrical Quertron.. I hate those

[scottfab]

Odd thing. Worked this morning like brand new. .???

Jim

sounds like an opportunity to check gas pressure as mentioned and other preventive measures. Maybe you have the dreaded contacts problem on the head unit.

[Racinfan83]

Mine on my truck worked until it warmed up. Then it would quit and not engage. When I took the clutch unit apart the electromagnetic coil was cracked. I assume that once it got hot it expanded and shorted or just didn't put out enough magnetism to engage the clutch plate. So if it quits when it gets hot - you might want to look at that...

[vettn71]

Good plan. I'll check pressure and contacts

Thanks, all
Jim

[Funracer]

Wifes Yukon A/C went out last summer. It turned out to be the mix valve
or blend valve. It proportions warm and cold air as selected.

Symptoms are blower fan works and temp goes full hot or will not
change settings. Some of the older ones can be opened and contacts inside cleaned. Newer ones must be replaced.

Check this if your compressor looks OK.

Good luck;)

[Starman]

Issue I had a couple of years ago with my HVAC in the ZR1, it would work fine when the car was started and then after 15 or so minutes would reset the set point to 75 degrees and then have to hunt the mix door locations. This is done by cycling the door full open and closed which takes over a minute in our cars.

Imagine the fun of full blast heat on a 95 degree day. I also caught some erratic exterior temp readings, like 178 degrees at times. This behavior became more consistent over about a year and I finally figured out that it was acting like power was being cycled. I pulled the control head unit and took it apart. It has a power supply capacitor of the same crappy quality as in the Bose amplifiers - replaced it and re-soldered what appeared to be a few cold solder connections and it has worked perfectly since. Don't forget there is a screw in the duct above the center console or you break that irreplaceable bezel.