Help needed understanding IHKA Climate control

[rv6john]

I have a 99 M3 that blows hot air from under the dash regardless of the temperature setting.

I did some research and searched the forums and the problem seemed to be the heater control valve. Installed a new valve and had no improvement. I have checked for power to the valve and there is a 5 volft drop between power in and either ground.

What I have been unable to find is an operational description of the whole system. I have searched the forums, Bentley and the ETM.

I am trying to figure out what regulates the temperature. Is it the water valve, the "regulator door" or a combination of both.

If someone could point me to a good reference or write up a description of what the sensors, switches and motors do, it would be much appreciated.

Thanks, John

[MParallel]

Did you check if you could get cool air coming out the other vents? If so, that would rule out heater valves stuck in the open position.

I'm not 100% sure if the e36 uses a hot/cold flap like newer systems (and if the newer systems still have heater valves) otherwise it could be this mixture flap stuck close, so no cold air can mix with warm air to get the desired temp.

Could also be a temp sensor somewhere in the heater box is broken and gives out false readings, causing it to blow hot air.

[nate2002]

im having this problem...i have cold air coming out the dash vents but blazing hot air coming out the feet vents. What is my problem?

[Flamingo]

im having this problem...i have cold air coming out the dash vents but blazing hot air coming out the feet vents. What is my problem?

I had this same problem, so yesterday I pulled out my CD player and discovered that the cable that goes to the hot/cold dial ( the one with the three red and three blue dots) had become disconnected from that dial.

I cannot figure out how to reattach it so I just pushed/pulled the cable ( it has an orange plunger type thing on the end) and low and behold, the air became hot out of the face vents.

Do I know what this is called? No. I also don't know if I need the whole assembly or can just get a new cable - Bentley does not show just the cable or what it is called- but for 5 minutes work- taking out the CD player- I'll do my own climate control myself.

When I want no heat, I just turn down the teperature dial and close the vents. Might be a ghetto way to fix it but being some what mechanically impaired, I do not want to even begin to take apart that dash. When it gets hot again, I'll jerk the player back out and do the AC.

Besides, that's what verts are for..get hot, drop the top.

[nate2002]

that works for you but i need ac...125 degrees doesnt work with a vert even if i had one. anybody? help?