Could anyone advise what is the easiest route for replacing the aux fan ballast resistor on an '86 300SDL? It looks like the master cylinder and resevoir may have to come out?

On another note, I mistakenly ordered an auxiliary fan switch from a supplier and received a single pole (red topped) 100 degree Centigrade switch. I'm not sure where this switch goes or does. The vendor said the MB part number is 006 545 1424 but couldn't tell me its installation location or exact function. No doubt, someone can set us straight on this.

The only switch I could find that looks similar is a 50 degree switch screwed into the block behind the water pump. I am told that switch adjusts transmission shifting characteristics.
Thanks for any advice.


Dave Jonas

'86 300SDL 138 k mi.
'84 300TD 240 k mi.