A/C problem- 95 Jimmy SLT 4x4

had a 96 Blazer(I believe the same control assembly) and a GM#

16205775 fixed it. The AC Delco short number is: 15-72204. Make sure, if you order it, that a 95 is the same no# as a 96. I'd bet it is. The hissing that you speak of makes me think that this could be your problem also but...They have a current list price of 134.74-you may be able to buy cheaper or look again at local yards, internet, etc. Good luck Andrew, JP

Your only problem is a vacuum leak or either a bad vacuum check valve. The blend door is vacuum operated and when you loose that vacuum you will get the symptoms you're experiencing. You should be able to fix this yourself depending on where exactly the leak is. If you look behind that center console, you should see a bundle of colored vacuum lines running from the control switch over to the evaporator/heater core case. You'll also see a check valve located in one of the vacuum lines. This valve may be going bad. It would be a lot easier to wait until you hear the leak again and then crawl up under your dash and see if you can isolate exactly where it is. These vacuum lines don't naturally deteriorate or break so you might look at where they connect at the control/case to see if maybe someone accidentally kicked one of the lines while sitting in the passenger seat.

Thanks for the vote of confidence and the light at the end of the tunnel. I'll let you know. Thanks again Jerry.

Andrew.

As other have wrote, you probably have some vacuum issue. Many of the S series of that vintage have a ball shaped vacuum reservoirs mounted under the hood on the drivers side. CHeck all those hoses for condition and replace any that look cracked or deteriorated. Try to find the check valve and see if its working. While your at it, check ALL the vacuum hoses under the hood.

If you have a leaking vacuum motor under the dash, you really need a hand held vacuum pump of such to trouble shoot it. One with a gauge on it. Once you take the hose assembly off the control pot, you can feed vacuum to each vacuum motor through the hoses and then see if the vacuum leaks down. A leaking vacuum motor or bad hose should start leaking down quickly. I had a bad actuator on my taurus i trouble shot and found it using this method.

Bob

If it's a leaking vac motor, it ain't a do-it-yourself project. The dealer had to pull the ENTIRE dash out to fix my 95 Blazer when the vac motor died.

on Tuesday 21 August 2007 04:59 pm, someone posing as AWN took a rock and etched into the cave:

If you need - and if it will help - drop me an email. I've got a Haynes manual from my long-departed '95 SLE. (I got 150,000 miles in seven years from that truck.)

It could use a good home.

I wouldn't think pulling the dash would be fully beyond my scope but it does sound a little time consuming and tricky. Thanks for the heads up. If it's the vac motor, what symptoms might I have other than those that I decscribes already? What exact symptoms did you have before you took it to the dealer for the RE/RE?

Thanks! Andrew.

I truly appreciate the offer to help but I already have both the Haynes and Chiltons for my vehicle. Now... If you have an IATN or MOD password.... Thanks again! Andrew.

It would only blow air as if it were in defrost mode....nothing out the dash vents. The vacuum motor that moves the flap to redirect the air had failed....and defrost is the "failure" mode. He didn't pull the dash completely out of the car, but disconnected everything from the firewall and pulled it back away from it so it was like lying in the front seats. There are either two or 3 of those motors in there and I had him replace them all while he had it open....I just knew another would go out a week after the first got replaced :-)