I recently installed a Whipple S/C on my 5.4 3 valve. I had a custom tune done it at a local shop. I also installed the electric fan conversion from a later model F150. I installed the painless fan controller and had issues from the start. After receiving the truck from the tuner everything worked great. Had allot of issues with a miss under load on the passenger side. Turned out to be one bad brand new ford racing plug. The electric fan controller started acting up causing the truck to get hot and giving me the reduced engine power readout. After getting a new fan controller from painless the truck would continue to have issues when running highway speeds. running 70 the temp will ~220. When I step on the throttle the temp climbs above 240 and that's when the gauge pegs out and I get the alarm. I pulled the engine , it was rebuilt 40K miles ago, and had the machine shop look for a bad head gasket. they found nothing that would indicate my issues. I had ARP headstuds installed and put the engine back in. I ran it yesterday for the first time and same issue. I ordered a new thermostat and will change it this Tuesday. Truck idles smooth, when I get the alarm the coolant isn't hot and spewing out. I have an IR camera and used it to look at the temps. The temp sensor was reading 220 but the return coolant hose was reading ~140. the supply hose was reading ~100 degrees. Has anyone had similar issues.

 

I found my problem, bad thermostat. I know all the top techs on this forum were busy answering technical questions like driving in snow while in 2wd and how to remove the oil pan. When I was ten I repaired a flat tire on my bike.

 

I'm no tech but that would be the first thing I replace.

BTW, love the electric fan and Painless controller. It's been two years and so far so good.
The only thing I don't like about the painless controller is on highway even with my VSS sets at 30 MPH limit the the defrost ON will cause the fan to come on momentary.

Why have the VSS limit but yet it is not overruled?