From: Pirtle, John [John.Pirtle@ceridian.com] Sent: Wednesday, September 06, 2000 11:39 AM To: 928 OC List Subject: RE: [928OC Public] Climate control trouble I've been working on my a/c expertise recently on my new-to-me 87 auto... If you have hot air then it likely is the heater valve. Remove the air box. >From the passenger side you'll see a black/white plastic valve in a coolant hose running from the engine. The hot coolant comes OUT of the engine at this point. The heater valve should be installed with the BLACK side towards the engine (mine had been installed in reverse and that definitely does not work!). Reach in there and push the valve arm in and make sure it is not stuck. The valve arm IN closes OFF the hot water flow. You can check the valve operation by starting the car - move the hvac temp slider to the max cold position and then watch the valve to see if the arm moves to full close. Then move the hvac slider to hot and see if the arm opens. Even if the valve works it could still be leaky. If you think the valve is old, get a new one (about $15). If the valve does not move, remove the vacuum line and use an extra piece of line and suck on the valve and see if you can make it move. If it moves now, you'll need to remove the driver's carpet panel, find the white vacuum line and check it out (I bought a vacuum pump/gauge at Sears). Besides this problem, my a/c freeze switch has been failing gradually over the past 3 weeks. This switch toggles on/off the a/c compressor to keep it from freezing up the lines. Open the hood. The switch is under the plastic panel at the base of the windshield. Smack in the middle is a small silver metal box. On the driver's side are two electrical connections - purple/yellow wire towards the front, brown/yellow wire towards rear. You can test by bypassing the switch - make a little connector to plug these two wires together. I did this last weekend and my a/c compressor is now running all the time (NOT a good thing, so don't run it for too long or it will cause freezing). My symptoms were that the a/c compressor might not kick on at all, might kick on and work for only 5 minutes, etc. Other related events worked normally - radiator fans spun up, passenger footwell vent opened, etc. I haven't priced the freeze switch yet, but I understand it isn't too much. Be sure to check the Tips section at http://www.928oc.org. I've also posted some of my own email "keepers" on my web site. http://www.928gt.com sells heater valves. John Pirtle Atlanta 87 Auto http://members.rennlist.com/pirtle http://www.928oc.org -----Original Message----- From: Randy Faunce [mailto:Penless@compuserve.com] Sent: Wednesday, September 06, 2000 12:05 AM To: Bill Witcher; 928 OC List Subject: [928OC Public] Climate control trouble -------------------- Begin Original Message -------------------- Message text written by "Bill Witcher" "The a/c works sometimes, then next time I start it or go to my electrical guru is works. Assume it is electrical and have read a few posts on the subject, but anyone have ideas or similar problems." -------------------- End Original Message -------------------- Hey Bill, It may not be your A/C's fault. I would kick mine on and get HOT air, turn it off and still get HOT air - didn't seem to matter what I set it to - HOT air!! Turns out, the vacuum line that closes the heater core's spring valve (a little spaceship looking bulb installed in a heater hose just forward of the firewall) wasn't vacuuming enough to close it (spring valve and it's diaphragm are fine). Hope this helps . . . Randy (Faunce) penless@compuserve.com 317-861-0755 '88 928 S4 5-speed 232 k miles