Guys,
Ive looked over this setup about 100 times and cant seem to figure out whats going on. I have a 3 core champion aluminum radiator with dual fans attached. I purchased a Derale 35 amp control module for the fans. Wired it up exactly how the instructions state ( I did not wire the optional manual override as I did not want to add a switch).
When I fired the car up , it worked great. First fan kicks on at 180 degrees and the second around 190-195? Problem is when I shut the car off the first fan stays on. Now I thought that it just needed to cool engine down for a bit before it shut down. However at 100 degrees the fan was still on. Have to disconnect the battery to shut off. So what gives? I even exchanged the module with another with the same problem , so I know its not the module. Wiring is correct. Are my fans drawing to much amperage possibly and keeping the circuit breaker stuck open? Im up for suggestions at this point. Thanks!

how did you wire it.

Sounds like one of the fan thermostats is not working.

well that does depend.

did it come on immediatly?

does it still come on when you hook up the battery?

it could be the low end doesn't work, but 2 of them? or is that seperate from your controler?

if so, swap them between fans and see if the on follows it.
if not,seems more likely you crossed up wiring somewhere, and you are back feeding past the thermostat switch.

so while you think you wired it perfectly, it would be best to go over what you did.