a/c heater system

[z32tt1990]

Hello other z owners,
so my heater hasnt worked since i bought my 1990 300zx tt. the automatic climate control light and system work, but all it does is blow air. no change in the temperature regardless of what its set at. i have read somewhere that there are a series of motors in the system that could be malfunctioning? i was wondering if anyone could help me.

[grayman_TT]

Have you tried bleeding it to make sure you don't have any air in the system?

[z32tt1990]

in order to bleed i would have to take it into a shop correct? the coolant is full and recently flushed, so i feel like even if there was air in the ac system some heat would come out, but none does. and thats when it is set on full heat even. when its on the lowest set temperature the air temp doesnt change still. im not 100% but its my understanding that if the system wasnt bled properly, it would work partially? and would bleeding it even help the heat function, or make any difference to it?

[z.Leinbach]

I had almost the same problem with mine, turned out to have a fat air pocket and the blend doors were stuck, stuffed a super long screw driver down the center vents and I guess it fixed it, bit only have dash air haha. But it all temps worked after I did so.

[z32tt1990]

i may bring it into the shop and see if recharging it helps. but i really dont see how that would help the heater

[z.Leinbach]

If it still has the R-12. Refrigerant in it it cannot be recharged, as it has been deemed illegal, I'd recommend getting the R-134A conversation, expensive but worth it

[javadave]

You are correct about the motors. There are 4 in total, 1 that controls outside air intake, 1 that controls where the air is output to ( defroster, vents, and floorboards ) and 2 that are used for temperature regulation. There is also a computer called the A.T.C. Amplifier which controls these motors as well as the blower motor speed, confirmation beeps and indicator lights.
You may also want to check that the heater core hasn't been bypassed, in which case nothing you do short of replacing the core and reconnecting it will get you heat. Age or improperly grounded audio equipment can cause them to start leaking and replacing them means alot of work. Luckily the auto air control system can perform its own diagnostics much like the ecu and tcu.
Here's a link to the relevant starting page of the FSM, and good luck finding the problem.

FSM AC/HEAT Section

[z32tt1990]

when i did the test i got what appears to be the set numbers for everything? 30 40 50 and 00. im not quite understanding the high and low switch's role in this im guessing but from what i can see as far as i have read it has "no problems" but still wont blow air any hotter or colder than the air temp outside.

[z32tt1990]

i just did every variation of the test you can do. no trouble codes and as far as the A.T.C. is concerned my ac/heater are working to full potential. even with the tests when the vents are supposed to be putting off full heat, no trouble codes, yet there is no heat.

[z32tt1990]

If my butthole is red and itchy should I see a doctor. Any advice would help, Thanks!

[z32tt1990]

left the room with my computer on and my friend thought that was clever. ^^

[z32tt1990]

ok so i pulled out the plastic panel that covers the center air vents and exposed the blender motor, or what i assume to be the blender motor. there were two doors. one was white and much lower and the second was a black door that covered the entire vent pretty much. the black door opened and closed when i change the temp on the black door mooves. the white door does not. no heat is coming off of my heater core when i turn the heat up, but the heater is not bypassed. so does that white door have anything to do with this? can any one else give me anything other i can try to maybe see what the problem is?