Hi everyone,

I have been running the original Derale #16759 Adjustable Fan Controller for years along with the along with the mod posted over at gmtips.com. Recently, the unit gave out. I ordered 2 more units, and now I see that new units are no longer utilizes a positive switching circuit.

I have been trying to figure out a new diagram that would work like the old one, but have not been successful. Wondering if anyone on here can lend a hand or point me into the direction I need in order to figure this out.

I have attached gmtips reworked diagram and the new derale diagram and the old derale diagram.