oh yeah I completely forgot to put that in I thought I might put it in at the end but had posted it without
here it is

1975
240D
W115
3rd version
Australian car (if that's relevant)

And I should have that switch because THERE IS WIRING FOR IT
we had to remove the ac components and compressor but we are putting em back now to rebuild it

most appreciated to come back and have the forum say at least one reply

thanks jeremy