I am fixing up a few things on my recently acquired 1986 505 SLi wagon. After finding that someone had previously permanently locked up the electric clutch on the cooling fan, I have resurrected it. I found a second hand brush and holder, cleaned up the slip ring, adjusted the gap and away we go.
I do have one concern however. I have been led to believe that there should be a diode in the power wire supplied to the clutch (via the temperature switch on radiator) to prevent current generated by the free spinning fan flowing back into the fuse board. If this is the case, where is the diode and how do I test it?
Is there anything else in the electric clutch setup I should check (apart from the correct engaging of the fan) before I drive the SLi?
Thanks in advance for any assistance.