A/C Compressor only comes in "heat" mode.

[renewergy]

Hi Folks,

Hope someone has a simple answer for this. The A/C compressor on my '84 190D only engages when I hit the top “heat” button of the controller. The A/C button does nothing. I am currently converting it to run on WVO so I was tooling around in the engine compartment before the problem started. The A/C worked fine before that. I have already tried a new (re-built) controller and it still is exactly the same.

Any ideas???

Thanks...