1990 iroc dual fans wont come on...checked for voltage at replays bout relays had power...previous owner cut both power and grounds on the fan harness reconnected both let car warm up fans wouldn't come on...checked for voltage where I added male/female plugs only 1 fan has power going to it...if I ground the fan to the battery it will turn on...
Kinda lost on what to do next or where too look new temp switch between cylinders 6 and 8 new relays and no other noticable gashes cuts in wiring ant help appreciated

 

Assuming its the same for a 1990 (these are from 1989), you can apply a test ground to the Green/White wire on each relay to activate the relay and that fan should come on (you don't need the engine running or anything on). It's a good test for the stuff at the front of the car. If those work then its something below the green/white wires in the diagrams.

 

both fans don't come on unless requested too

 

Yeah doesn't the second fan only turn on when the engine gets really hot? I think I remember reading 235 on a thread somewhere.

 

Yeah I let the car warm up hitting the red zone on the gauges and nothing turns oj you can hear the coolant bubbling and no fans turn on...

 

 

This is the correct 90-92 1227730 ecm schematic for the fans.