The 1.8 volts was from the wire, it read 0 on the middle pin with the 12v hot and ground only connected to the resister. I did confirm the issue is the AC/Heater control. I'll post more details when I'm done but I found a control module off a 2002 SLK230 for $10 at the salvage yard. Looked way different from the back but the plug is the same. I hooked it up and all problems resolved!

So now I'm trying to see if I can change the temp wheels otherwise I'll have to shave a bit off the wheel area to fit it in the same trim piece.
Everything else is exactly the same size. the buttons are black and the dials are black, surround section is white.. The snowflake/ac button is actually opposite on this one.The EC button light on turns OFF the compressor (outside air only)and red light off means AC is on. Compressor must be controlled by the dials or something.