12VDC Fan Controller this one is rather small and cheap but not many of the options offer fahrenheit so I chose this. Has worked well for a year running 20 watts of fans. Searching on eBay or Amazon will net tons of options.I'm also trying to figure out this issue with my zapco st 4xsq that goes into shut off mode and it comes on automatically after about 10 minutes of cooling down i guess? I need to start measuring actual heat sink temperatures and write them down. Any thermo controlled fan kits recommendations would help the op and my self , thanks in advance guys!