Both won't be able to be on at the same time if your using the CCRM. The relays inside are not set up that way. It's either one or the other..
For race applications I would recomend having an independant sensor and 2 relays for the fans. either set them up to come on at different temps or both come on at the same temp
Ah, okay, thanks for letting me know. I'll have to do some finagling then.
Regarding the separate sensor - why not continue using the one the ECU uses? I can tell the ECU what temp I want the fans to come on.