Air-conditioning Problem

[Jeff H]

I have a 1996 LS 400. I was hearing a high pitched whistle coming from the engine bay, but before I could get it into the shop, the A/C quit working. There is no power to the controls, and no clock or outside temperature reading. Could this be a water pump issue?

[curiousB]

Sounds like the AC compressor seized and then the belt started to slip and squeal. I suspect the fuse then blew killing entire AC system power. With power off the AC compressor clutch released and now maybe the squeal is gone?

With car running do you see the serpentine belt running freely (with AC off)? Also if you drive for a bit does engine temp stay normal? If so water pump probably OK.

Too bad, a water pump might be cheaper repair than a seized AC compressor.

[IS400]

It could also be that the system lost pressure suddenly due to a failed seal and disconnected the compressor and disabled the system.

Get someone to check the refridgerant level before mentioning the failed system. If it is empty a recharge will allow the compressor to function again and then you can start looking for leaks rather than replacing a compressor that is working.

Just a guess, since that is what happened to mine.

A couple dollars for a seal behind the battery and I had ice cold ac again! :)

[Jeff H]

Sounds like the AC compressor seized and then the belt started to slip and squeal. I suspect the fuse then blew killing entire AC system power. With power off the AC compressor clutch released and now maybe the squeal is gone?

With car running do you see the serpentine belt running freely (with AC off)? Also if you drive for a bit does engine temp stay normal? If so water pump probably OK.

Too bad, a water pump might be cheaper repair than a seized AC compressor.

Thanks for your reply!

Serpentine belt seems to run OK water temp is normal in all situations.

Any idea what is resonable to expect for this repair?

[curiousB]

I would play out IS400's suggestion as the cause first. That would be fairly simple and reasonably priced. Guesstimate under $500. If it truly is a seized compressor it’s going to be >$1,000 as the compressor alone has a list price of $742.68 ($512.73 at parts.com) and probably another $500 in labor, refrigerant, and misc (drier/dehydrator).

Maybe a new seal, refill of refrigerant will be your solution. The thing that makes me think its compressor is the noise you heard. I wouldn’t expect a leaky seal and pressure shutdown to make a lot of noise. Maybe the noise was coincidental and unrelated. Cross your fingers IS400’s right.

[IS400]

Another thing to remember is that you do need to pull a vacuum on the system before you refill it for the long term. It is fine to throw a few cans of 134a in it to see if the compressor will work or not, but all the moisture needs to be removed by vacuuming for about fifteen minutes before refilling permanently.

You can pay a shop to refill or buy an ac vacuum from harbor freight tools for $30. Just make sure to have an air compressor available, that is what powers the vacuum. The fittings to make it work will be under $10. If you have a friend that is even just a little mechanically inclined, you should be able to vacuum and fill the system with no trouble at all on your own.

Good luck!