reads about 85 high and low side. My ac compressor makes a loud light grinding noise when the ac is turned on. I recently replaced it so its brand new.

 

If the high and low side pressures are the same, it is not pumping. Do you see the compressor clutch turning with the pulley when you turn on the a/c?

When did you replace the compressor and how long was it working well?

 

My question would be what is the ambient temp? Or are you checking in a heated garage? Seeing as it is the winter season, if it's below 50°-55° ambient, the compressor won't run, iirc.....

 

I have to ask, because new compressors do not come filled with oil
did you put oil in it when you installed it....and did you change the condenser, orifice tube and dryer?
clean any debris out of the system?

 

I replaced condenser and orifice tube and gaskets. It was running for a couple months granted I didnt drive it much. It went out at the end of a 20 minute drive taking a turn. I live in Florida so its not cold right now. No it does not look like the clutch is spinning with the compressor.

 

It came with oil inside it.

 

I dont think its an electrical issue because I unplugged and plugged in the ac compressor and it only makes a noise when its plugged in.

 

I tried to spin the clutch with my hand it wont spin.

 

A brand new compressor will be hard to turn by hand but it will turn. One that has run for some miles should turn relatively easily by hand. It sounds like your compressor has seized if you cannot turn the clutch by hand. If it is, in fact seized, that may explain the scraping noise you hear when you turn on the a/c. Does the paint on the clutch look like it has burned off? When a V7 compressor seizes, it either breaks internally sufficiently to rattle around broken parts or it locks and causes the clutch to slip until it overheats and lets go.

You describe a noise only when engaging the a/c but say the clutch does not rotate so my guess is you have a seized compressor.

 

I have a question. Why was the compressor replaced? Was it a leak, or did the old one seize up? If the old one seized up, it may have contaminated the entire system with junk. If that happened, and the system wasnt flushed out, you have simply reinstalled the problem. Because the matallic junk in the system has now caused the new compressor to seize. My .02.....

 

I'm probably going to pull it out again and have a look at the compressor. The old one had a leak coming from it. I bought the car like this so I dont know anything other then the dye I saw all around it. It would also lose freon in a day.

 

Youll be ahead of the game if the old compressor didn't seize up or contaminate the innards!! Also, some compressors come with "some" oil in them, but not totally full with the proper level. Who installed the compressor?

 

I installed it. It came with some oil. According to the corvette factory directions more could have been added but I opted not to because Im thinking it comes that way prepared and I shouldnt mess with anything.

 

It is necessary to do an oil balance when replacing a compressor and other components. The idea is to keep the total system charge at 9 ounces.

 

It all depends on who filled the compressor, and with how much oil. I do know that from the majority of the posts I've read here and other places, most compressors do not come with the total amount required. This could explain why the compressor will no longer spin, correct?

 

I am trying to spin the clutch by hand it is in deed stuck. This is a brand new compressor used for only about a month.

 

You will find a good AC Delco A/C Service document here:

https://www.corvetteforum.com/forums...post1607386295

It does have a chart about oil balance. From what you described, you did not account for the oil removed from your system when you replaced a few components along with the compressor. Depending on how much trash you find when you pull your orifice tube, you will want to replace the accumulator dehydrator along with the compressor at a minimum. If you find debris then you need to decide about replacing the condenser or flushing it and flushing the evaporator and lines. You may also get a feel for debris by draining the oil from the compressor ports and the compressor crankcase and looking at it and straining it through something like a coffee filter.

If you do flush, at least you will have a zero oil baseline. Then you can add a full 9 ounce oil charge.

The AC Delco guideline also describes use of a suction screen and a filter in the liquid line to protect the new compressor. Lately I have been advocating use of the suction screen in compressor replacement related threads because the screen will reduce the amount and size of trash that can enter your new compressor. Suction screen kits very similar to the AC Delco kit described in the guidance are available on Amazon for about $20. The AC Delco kit is no longer made but there are sellers on ebay that have NOS.


Amazon suction screen kit.

Airsept 67650 Air Conditioner Compressor Suction Screen Kit

 

I just looked in the orifice tube I didnt see anything maybe microscopic dust. When it was stuck I really didnt run it at all. Im going to replace the orifice tube just in case.

 

The compressor I am purchasing is going to come Prefilled with 3 oz. of OE-Specified Oil. The total system holds 9 oz. I dont know how much was in the previous one. Reviews say over 7oz but Im also reading over filled systems with oil shouldnt cause many especially immediate problems.

 

Well that is good that you do not see debris at the orifice tube.

My thoughts on oil balance:
1. You wrote that you replaced the Condenser. The AC Delco document I posted has a rule of thumb for how much oil is retained by the Condenser so I suggest you add that amount of oil to account for your "new" condenser.
2. You should drain the oil from your failed compressor's crankcase and the suction/discharge ports and measure it. The AC Delco document gives recommendations for how much oil to put in your new compressor based on how much is drained from the old.
3. You have not written that you replaced the Accumulator/Dehydrator. You really should replace it so that you have a fresh dessicant bag to absord moisture. The AC Delco document also gives recommendations on how much oil to add for a new A/D.
4. You will not hurt your compressor if you wind up with a BIT too much oil. Yes, there will be a small a/c perforformance degradation with an extra ounce or 2. If you live in a very hot climate, you might notice it on the hottest days when your car has been soaking in the sun. Back in the day when we (Delphi and GM) used to have an 8 ounce oil charge as OEM I added another ounce in my vehicles because it left more oil in the compressor crankcase which was better for compressor durability.