73 Z + A/C + Heater Question

[jaltman]

I am a relatively new 1973 240z owner. The car has the after market a/c in it. I have been very impressed with the knowledge contained in here, I have answered many questions just by reading, thanks all.

However, I think there is a easy answer to this question, but what it is eludes me at this point.

Had my first oppotunity to need a lil heat in the car. The heater controls did not work exactly as I expected, but that could be because of the way the a/c sits on the air input. Nonetheless, all was well, except than when dumping heat out the bottom, while the passenger seat side was toasty warm, the drivers side was nothing but cold air.

I suspect some flap is not completely opening but since all this is located so deep under the dash, I was hoping the colective wisdom might point at an easy adjustment or other wisdom. Perhaps the control cable is just not properly adjusted.

I also noted that the facia air vents never really stopped having air, but I would suspect that a flap originally had some foamy material to seal it when closed and that the foamy material perished long ago.

Any thoughts on my cold air at my feet would be appreciated.

[GreenZZZ]

Check out this thread that shows how the flaps operate.

http://www.classiczcars.com/forums/showthread.php?t=23409

Mine had to be pulled, blasted, painted, repadded. Took a LONG time to do the job.

[jaltman]

Ah! Very good information and photos! However, it still eludes me how I can get hot air at the feet of the passenger and cold at the feet of the driver. It would appear that they are two doors from the same space after the heater core.

Perhaps hot water is not completely filling the heater core and one side is hot and the other not?

Let me point out the passenger side is HOT and the drivers side COLD! Not like there is any mixing or lukewarmness about either side, quite extreme in the difference.

[GreenZZZ]

Move the temperature control knob and watch the flaps move. You will probably see one flap is moving and one is stuck open or closed. Usually the passenger side flap will rust up and not articulate due to the water heater lines being located on that side and a coolant leak getting them wet. Sometimes the driver side flap will rust up if the heater core leaks on that side. Sometimes the rod inside the heater box which connects to the flap comes off due to a badly done heatercore repair done in the past. Get a flashlight, move the temp knob, watch what the flaps do, free any debris restricting movement of the flap if there is any, report back.

[ZCCOR#109]

I would add, that the A/C hung below the heater air inlet will restrict some of your ability to view the operation of the "flap" that opens and closes the various "outlets/passages".

You may have to drop the A/C unit away to view and correct.

Also, the several plastic hoses/ducts that route air may have come loose or been removed. They slide over metal outlets and are held in place by small metal screws. Difficult to remove and replace those screws. maybe previous owners didn't and the plastic air duct "fell off".

PS

if your after market A/C is like mine, it only operates on interior air.

that is to say the exterior cabin air sources are shut off, and the cabin air is routed through the a/c evaporator and then into the existing heater room inlet and out the vents.

Edited September 28, 2010 by ZCCOR#109