HELP! 97 Protege overheating!!!

[J-Roc]

Hi all,
I'm in dire straits here...This could get very technical, so please bear with me. My 97 Protege is overheating because my fans dont turn on I get no engine codes. I hotwired the fans and they check out okay. I also checked the relays and all check out good. I removed the coolant sensor on the head, next to the distributor and the back-up fan turned on- not the main fan. I thought it was the coolant sensor, but replacing it did not help I hotwired the fan relay in the fuse box on the drivers side and the main fan turned on. It seems that the relay is not receiving the ground signal when the engine warms up, thus the main fan is not turning on. My question is this: Where does the main fan relay receive the ground signal from? If anyone has a schematic they could show me, it would be greatly appreciated. Much obliged!