Rebuilt electronics advise for E23

[BMW735i87]

Anybody have any experience with ProgramInc on reman electronics. Looking for the HVAC pushbuttons and thumb-wheel, has ACC.

Thanks.

[Hit Man X]

Programma is junk. PM me and I will give you contact details for Kris Rose.

[8991XJ]

or if you DIY, www.e38.org/e23, lots of projects and the switch rebuilds are there.

[BMW735i87]

I would give it a try, saw the microswitch replacement but the symptoms do not match. I have not been able to determine the fault so in spite of my reluctance to start throwing parts at it, this is where I'm at. To summarize, heat blows whenever the blower fan is on no matter where the temp thumbwheel is set. I checked voltage to the heater control valve vacuum selenoid, and sure nough, it looses voltage when I turn the blower fan thumbwheel on any speed, and then it opens the heater control valve. Again, no matter what temp the temp thumbwheel is on. I also tried warming up the inside temp sensor, no change.

[8991XJ]

This system runs on vacuum. Might be a vacuum leak at the reservoir T under the cowl passenger's side.

[BMW735i87]

I put a vacuum on the entire vacuum circuit with the engine off and it goes right up to 15 and holds it, the control valve also holds a vacuum as well. It is the loss of voltage to the control valve vacuum selenoid that causes heat control valve to open and allow hot water to enter the heater box. None the less, I've read enough to know those plastic tee's are out, so great point on that. I live in Michigan, and whether it has an effect or not, all my lines and that kind of stuff doesn't dry out like it would in a arid climate like Arizona or similar. One other thing I just thought of. There is a vacuum check valve in the vac line going from the plenum to that emissions vapor diaphram thing on the intake bellow. The big line from that diaphram goes to the charcoal filter I beieve. Anyway, that check valve prevents engine vacuum from getting to that diaphram, ie. the check valve checks that vacuum cannot travel into the plenum. That seems odd.