[RocktimusPryme]

Is the low/high on the dual Contour fans just one on vs both on, or does each individual fan actually have two speeds?

Here is an interesting one I stumbled across

https://board.moparts.org/ubbthreads...cs/723498.html

Mercedes fan with a built in soft start. Looks like it would work.

I found that while looking for a 4 wire Mercedes wiring diagram. I have a more modern Mercedes bosch brushless (probably PWM too) fan that I got at a swap meet for $5. It has a massive 19" blade. Ive been looking for an excuse to use it. I can hot wire it on using 3 of the 4 wires, but I don't know what the 4th wire on it is for. I assume for use controlling speed with a PWM.