Dear Friends!

We have an A/C issue here. And we would like to get some advice.

Problem is clutch is broken, but deatails.

Me and my brother both have a 3.1L V6 Firebird, what we use at the better road condition days of the year, mostly in summer. And as this time getting closer, this issu need to be solved.

At the last summer my bro went a trip with his car while A/C was in use, and he noticed its getting weaker and when he stopped with the car he noticed a noise. Opened up the hood and it was clearly the clutch broken and rotating freely.
After he returned home we noticet the compressor looks like locked up and the engine trough the belt broked the clutch somehow.
We thinked the compressor was faulty..

We had an other good working spare unit. So i taked the car into an A/C shop. A technican discharged the system, then I replaced the complete compressor, and asked a refill for the system. The technican did a vacuum test to ensure no leaks, and then he refilled the system according the stickers on the car, and added 1KG of oil compound too.

Then we tested the car shortly at the shop. Worked fine and blowed ice cold air.
I droved it home for about 20 min, and worked jst fine.
A few day later my bro went with the car for a longer trip again but after around 100km, the same issue happen with the compressor. The clutch is broken, and the compressor's casing looks burned.

As we know the A/C is a complete separete closed system from the car, and the compressor just flowing its contents IF, i set the A/C selector into one of the positions where it need to work. And this time thechically. A 12V freed came out from the unit to a presure switch (located on the drier) and if a prssure is in betweein the OK levels its pass it trough. (In too high or too low leves it did not closing)
So if it passes trough, it gets into the compressor's pressure switch whre the same happens. And if it passes trough let the compressor's clutch coil energized, and the whole system to work.
And in that case if a short or some kind of fail happen, in the worst case:
A fuse will blow,
The AC always will be energized.
The AC never work
But non happen..

So now we have two compresso wich looks burned, and its clutch broken.
We would like to repair both compressor, but we would liek to find and understand the probleme befere we killing a third compressor.
The car did not have any electrical issue for yeras and never around the ac. So we do not think is an electrical issue but anything can happen.

Hope someone can suggest us help.
Thanks for any kind of info.

 

After reading your post , my only two thoughts are these ;

#1 , could you have had two bad compressors ? The factory supplied compressor on our cars is not very highly regarded here , in fact SO many people think they are junk that there is a modification where a "Sanden" (I think) unit is adapted to work in place of the original .

#2 , could the system have been over filled , not to the point of activating the high pressure cutout , but overfilled enough to strain (and destroy) the compressor ?

PS , some pictures of both failed units may help determine a cause ....

 

The spare compressor came of from a working car, with a working AC. And we stored it for bad days. It was in dry place in my garage.

The shop technican checked the datas before, in process and aftrer the refill so i think the fill quanty was right.

I Will take a few pictures in the following days to others can see how they looks like.

 

Something with 1KG of oil is not correct, should be in volume measurement. Refrigerant is around 1kg and i believe around 180ml or so oil is added. System has to be fully flushed both directions if old compressor failed and sent debris throughout the system. A constantly tripping low pressure or high pressure switch can burn up a clutch.

 

So replacement presure switchs is up to the list, to we have spares in hands. But hope pictures Will tell more about the damage.
About the change process, due it can be done in auto A/C shops the technicans there should know what they need to do…
Hope we have a failing switch instead of not knowing service shop

Any tip for testing these switches in this current state? (Not working compressor, System charged)
Also the Compressor coil is worth a measure with the DMM compared with my working car, to we know its shorted or not.

 

Sounds like when the first compressor died, it shed debris into the system; then when the second one was installed without flushing everything clean and replacing the accumulator and orifice tube which were filled with metal chips, the debris destroyed it as well.

 

Here is the pictures (from both compressor):https://drive.google.com/open?id=1ru...ROW6-gsFcWkFSV

 

When the compressor fails, the entire system has to be flushed. Depending on the condenser, the condenser cannot be flushed and will have to be replaced. You may be able to flush the evaporator without removing it. A new R4 compressor may last 3 hours or 3 years. It's just a gamble. And every time you lose the compressor you have to replace the condenser and orifice tube and flush the system. Save yourself some grief and do the Sanden conversion. I used a kit from https://www.originalair.com/88-92-ca...-r134a-stage-2. Has everything you need in one box. Save yourself some time, grief and $$$ and do the conversion. I gave up on the R4 after the third NEW compressor failed. And BTW, the Sanden is good to 6,000 rpm.