Its hard to believe the last time I visited this site was in 2012. Anyway on my 84 300d I somehow managed to get all of the climate control buttons stuck in. Normally when you push one button another will pop out. My car has been sitting for the last 5 years at least and I cannot remember if the climate control worked or not. I am getting my car back on the road so the first thing I'm tackling is the climate control. I pull out the climate control and low and behold I see a huge burn mark in the circuit board. I looked into getting a remanufactured unit but I decided to try and rebuild the one I have by buying a used control panel off of ebay. I found a control panel for about $40 and started to tear into it. I took the best components from both control panels to make one good panel. I fixed and reflowed every single solder joint on the control panel in order to get rid of any micro fractures that might be there from age. One problem I had to tackle was the fact that the climate interlock switches were not working properly. This caused me to de solder all of the switches to see how they functioned and see if a repair could be made. I discovered this plastic piece that lets the switches stay pressed when you push a button was broken and caused my defroster button to never stay on when pressed. I thought about trying to source another interlock switch setup but decided to try and make the plastic piece myself. I measured the old plastic piece with calipers and designed a new part in solidworks. I then used my 3d printer to print out the plastic interlock and now all the climate control buttons stay engaged or disengaged when they are supposed to.






switches with new plastic interlock installed

new plastic interlock next to old

chipped plastic interlock that would not let the defrost button stay engaged

 

Wow! I wish I was that handy.