THENOBBLER

Hi,

I just had the a/c system on my 89 coupe re-gassed, and very successfully too - all the lines that should be cold are so chilly there's condensation forming on them. This is good. The bad bit is that there's still no heat getting into the cabin - clearly the warm / cold air mixture flap is stuck in the warm position.

Can anyone please advise me how to get to it? I'm guessing that either the flap is stuck in position or the temperature sensor and electric motor (or is it a vacuum unit?) are kaput. For clarity's sake, the temp control is two buttoms marked Warm and Cold, not a slider control.

I know I could just hook up the fluid inlet and outlet pipes for the heater to each other (rather than the heater), but that feels kind of crude. Any advice will be most welcome.

Oh, I already tried cycling from 60 to 90 degrees a few times, with no discernable result.

Thanks

Tony.

SunCr

For electronic air it's a motor mounted on the heater box in the passenger compartment. There's a plastic clip connecting it to the linkage that controls the temp door. To see what it's doing, remove the Blower Module on the left side of the Evaporator Case and as someone operates the Controls between 60 and 90, the door should move. If it doesn't the clip is usually broken. Remove passenger hush panel and ECM to access while laying on your back. If the door is moving, the heater core is plugged. You can try to flush it with a garden hose or compressed air. Otherwise it will need to be replaced. If it is plugged, check radiator (and pretty much everything else too). Galvanic corrosion is common on our years (leaking head gaskets - allmost always at #7) and once established all sorts of nasty things start to happen.

AGENT 86

http://members.shaw.ca/dankai/AC%20Electronic.pdf

DarkBlue88

One easy test is to drive it, take a hard left it should blow cool(or at least cooler) then a hard right should make it blow hot again.

the door has a threaded rod and a clip which breaks, as did mine, but it's an easy fix. some door lock rods have a similar clip, maybe as near as a parts store with the dorman/ HELP! parts.

Da Mail Man

.....i just went through this a year or so ago...advance auto parts sells a clip package with assorted clips where 1 of them will fit.....in my situation, the clip DIDN"T break but, for some reason the rod slid out of the stripped clip as it is aparently threaded into it..

..i reset the rod in the clip and put 1 very small drop of gorilla glue on it and so far, no problems at all...

..i think i remember reaching in and moving the blend door with a paint stick and also, viewing a clip through the fan resistor module at the top of the heater/ac box.....there are 2 clips involved..

THENOBBLER

Thanks for the help guys, I'll go take a look. Since I'm off to Le Mans on Thursday I'm less worried about making the door controllable and more interested in moving it to the full cold position! The last two years have been insanely hot...

THENOBBLER

Investigated and (temporarily) fixed. The diverter door actuator motor only works in one direction - hot. The actuator arm can be pushed back to the cold setting with a little bit of careful applied force, and I now have cold air.

Replacing the actuator motor doesn't look too difficult either. Anyway, thanks for the pointers.

samsonb

Got pics of where the actuator motor is?