DANdeMAN

OK, was on the highway AC working fine.
I wanted more cold air to go up the windshield so I pushed de lower *** all the way to the right were the defroster simbol is.
Then heat started to come out of the vents so I pulled back the *** in one of the other position and now I have no more cold air.
Even with just the vent open I can feel warm air even thoght it was cool outside tonight.
What might be wrong???
Checked the fuses and they look fine.

help, the heat is comming up here

85fortheDrive

Dan:

For what it's worth (not much) I just had the same issue today. Moved the lower slider over to the defrost setting, felt a blast of warm air, and then moved it back. Now the AC is nowhere near as cool as it was prior to that.

I'll do some keyword searching on the board here and see if I can gather any scoops. It's getting warmer here in Chi-town so it figures the AC would go south - eh?

Peace,
Tim

DANdeMAN

Thanks Tim

SharkSkin

https://www.928gt.com/T-WallyHVAC.aspx

To start, I'd say check fuses, then look into the current path from the HVAC head to the compressor clutch. You may need a fresh relay in the HVAC head, you may be low on freon, or a dozen other things. Start with the fuse and just be methodical. Do you have wiring diagrams?

DANdeMAN

I have the WSM on CD so I should have the wirring diagram.
It was blowing ice cold air before I move the slider so i don't think the freon is the cause but who knows!?
Is it possible that the heater valve got stuck when I put the slide on defross or it as nothing to do with that?

Thanks for the link

Mrmerlin

Hi it sounds like you may have lost one of the vacuum pots to the air mixer flap, open the left side console cover next to the radio , get myti vac and check vacuum on all of the lines IE see if they all hold vacuum, after checking the fuses and relays

the flyin' scotsman

Highly possible; when moving the selector to full defrost the system defaults to full heat and full fan speed toward the windshield.

Start the car with the lower air filter housing removed, select the position where the air is to the floor and windshield, lowest temp and AC button depressed and observe the heater valve which now be fully closed. If not either the valve has gone bad or there's no vacuum to the valve for quite a few possible reasons.

Let us know.

69gaugeman

I would first check to see that the compressor is coming on. When you look under the car with the temp lever all the way to cool, the front of the compressor pulley should sometimes be turning.

DANdeMAN

Exactly what hapened!

Where is that housing? Under the dash!?

Yes I will let you know..Thanks all for the great info..

DANdeMAN

Thanks merlin, will do that...

DANdeMAN

Thanks Rob, will check that to..

85fortheDrive

Malcolm et al:

Sorry to piggyback on Dan's post here, but I have a similar situation. If you don't mind, can I chime in with a couple related questions...

1. I'm supposing that my 84S is still using R12 freon. (No notes from the PO on this.)
Is this okay? I saw some bubbles today in the flow window, which means I might be a little low on coolant. Can I get R12 or does this signal the need to convert the system to R134?

2. The lower lever of the temperature control console is goofy. Sliding it fully left to O usually shuts off airflow. Sliding it all the way to the right (defrost) activates the blast furnace process and the windshield is defrosted in 0.0056 seconds. But the other airflow location settings do nothing. In fact, I have never felt air emanating out of any port other than the center console vent and the door vents.
(Occasionally, after a 7-layer burrito at Taco Bell, there will be bursts of air from a driver seat location, but I'm pretty sure this is unrelated.)

So I'm wondering how to get this airflow slider working and if it is a suspect in the not-very-cool AC problem.

Thanks and Peace,
Tim

85fortheDrive

By the way, thanks Dave for the HVAC link. I printed that whole web page out and have been trying to learn a bit about how the system works. Made for some tasty reading as I supervised the boys on the Slip n' Slide this afternoon. Boys having water fun, Dad fussing about the AC in the car. Must be gettin' warm in Chitown.

DANdeMAN

Today I removed the left consol cover to check if the actuator for the heater valve was working..it was not there. I followed the white vacum hose and landed in the engin compartment behind the air filter boxe. The actuator holds vacum but the hose does not - engine not runing.

I could not look at the heater valve in action, as the air filter boxe was removed in order to see the valve and there is to much debri around to start the car witout a filter. My question is : does no vacum equal closed on the heater valve?

Engine runing and AC on, I did not see any moving parts on the AC other than the belt turning. The interior part in the puley was not turning, is that the clutch?

BTW, I can't seem to find the dam "window" to see if there is coolant in the AC..GRRR

I took pics of most everything..will post pic tonight or tomorow.

ps; it looks more and more like a blown fuse or reley of some sort to activate the AC clutch..next troublshooting will be electrical.

69gaugeman

If you take that white hose that goes to the valve and remove it and have it sitting out when you push the lever to full cold and put the lever to the square box and open the center vent in the dash there should be vacuum on that white hose. Just put your finger over the end and feel for it to stick to the hose