I posted this on the tech forum but I thought I'd give the R129 forum a shot:

I've got a 1990 300SL-24 with a short circuit problem in the auxilliary fan circuitry. Basically, everytime the aux fans would come on, either by A/C or water temp, the aux fan fuse will blow immediately. I checked the wiring on both fans and nothing seems to be out of place or grounding anywhere. All insulation seems fine. Im a bit challenged when it come to electrical issues so I would appreciate if someone could help me out. Does anyone have a wiring diagram for this application? I was thinking as a last resort, just to re-wire the aux fan system but I would need a wiring schematic to do so. I think that a 1990 -up 300CE or 300E would be similar since we share the same engine? If anyone has any advice or suggestion, please post. Thanks in advance