I have an '04 with a 5.4l and I'm planning on putting an electric fan from a 2011 f-150 with an ecoboost motor in, now that after 20+ years we are FINALLY putting electric fans in trucks at the factory. What I'm wonder is if I run the relay setup, is there an output in the ecm I can control the fan with, and if there is, do I need to reflas the ecm to do it or find a ngs and turn that parameter or output on in the ecm... Didn't know if anyone was getting this deep in the electronics. I work on heavy duty trucks for a living and changing parameterization is a common thing

 

Um.. I don't have fans from an EcoBoost, but you're best bet would be just to buy a relay from the auto part store and set it at a certain temperature. I don't know why you would want to mess with the ECM and I doubt there is any way to control the fan through the stock ECM since these trucks never had the option of E-fans