I am working on a 2002 Internations 9400i with a series 60 Detroit. We've been working on this truck for years on and off to figure out why the engine fan runs continuously. Solenoid test good, fan clutch releases with shop air, wiring from the ECM to the solenoid has been replaced. When I give the solenoid ground it activates but doesn't when the ground is coming from the ECM. Any suggestions?????