Nasty water valve issue that drains batteries

[ADC E31]

Water valves always hot and drain battery

I have a recurring problem lately and discovered it by mistake. I noticed that my batteries drain rapidly. almost over night. By mistake i touched the water valves next to the positive post on the car and I got as heat blister instantly from touching it. I measured it with my FLIR camera and it was at 165 degrees. I looked at all the fuses and engine parts with the camera and the only thing active was the water valves. All the fuses and relays were room temp. Why is this happening? Could it be relay 33 stuck open or closed? I switched the relay with the one next to it and it still did not affect anything. Is there something else that I may be missing?

Before I start throwing parts at it, I tested the connection and I get power to the wires, of course. I have a brand new heater water valve (PN 64118391417) and plugged it in. I can hear the individual valves open, but then again, so does the one currently mounted on the car. What is wrong?

I looked for the heater control module or they call it RELAY BOXINDEP.VENTIL.SYS/-HEATER SYS. (61311379737) that is in the passenger side glove box (according to ETK). My car does not have the control module in that location. Any ideas where a November 1990 car would have the module?

I also pulled all the relevant fuses and listened for the water valves to engage and disengage. HELP!

[Timm]

The fuse relevant to the heater valves is F1 - if that is removed the heater valves should switch OFF - make sure they lose their 12V supply, if they don't something else is going on! I would expect that 12V to disappear.

The controller for the heater valves is the IHKA, which is located between the footwells in front of A/C unit and is a bit of a blighter to get to. It is possible that the IHKA has failed - but first make sure it is actually switching OFF (not powered). The water valves are powered ON to close them - if the IHKA is still powered then putting the drivers temperature control to maximum should switch them OFF - check that as well.

[ADC E31]

Thank you! This will be my quest for this week. I will look for the F1 fuse or is it fuse #1? I will start taking my foot wells apart and see what I find.