I finally manage to fit an auxillary fan into my 1974 SL350. Although I have the Haynes workshop manual with the wiring diagram I have a few questions.
The wire that pulls the compressor clutch in appears to go across the car, and without removing all the tape that binds the wiring loom, disappears.
Simple enough to run a wire from the compressor to a new relay with a new power supply wire so that whenever the air con. is "on" the fan is "on".
Also this can be controled by adding temp...