AC Woes

[NolliM3]

My AC has been blowing hot air when I turned it on...so I checked out what going on with DIS and got the following below (see pics). I thought it might be the mixture wheel and bought a used one with the electrical connector then; when it arrived, I uninstalled mine (95M3) and discovered it had the bowen cable. So that was disappointing as it means searching for possibly a broken or disconnected wire as well as there might be the possibility of having to remove the dash...a thought that's not sitting well with me. I have marked the location according to DIS with a green circle on the electrical diagram below. Interestingly, there is no pin 13 or I haven't found it yet.


It would really be pleasant to have AC when one lives in the south, so I hope someone experience with electrical components of the dash can guide me to a resolution. If I can get to a solution by just removing the glove-box would be awesome...I could change the cabin filter also while I am there.

[Mayorchuck]

I'm not familiar with the set up on that car, but from what I see here, I would be checking the water valves to see if they were stuck open allowing hot coolant into the core

[bmwdirtracer]

+1. It's a very old car, to be relying on DIS for diag of the A/C system. Check the hoses after the heater valve, to see if they're hot, with the a/c on. If the hoses are hot, test the wires into the heater valve to see if one of them has 12 volts+. If so, replace the heater valve. If there is not 12 volts to the valve, trace the fuse and wiring.

The heater valve opens if it has no power, allowing hot coolant into the interior.

You also really need to begin by having the a/c system evacuated and recharged with exactly the correct amount of R134a.

[NolliM3]

Thank you Mayorchuck and Chris for responding...I forgot to mention that I had replaced the water control valve first before using DIS to diagnose since I didn't have it then. After the replacement, it seems that it got worst.

[bmwdirtracer]

Check the hose temps into the firewall, and check whether the valve is getting 12+ volts. If it's not getting power, it will remain open, and provide hot coolant.

[NolliM3]

Check the hose temps into the firewall, and check whether the valve is getting 12+ volts. If it's not getting power, it will remain open, and provide hot coolant.

Chris, it might be Friday before I can report back...we have been having lots of rain as well as I have a differential output seal to do...thank you!