ISL Cummins Side radiator temp update
Thought I would update the forum on this challenge- background- we changed the engine hydraulic cooling fan motor chasing an AC problem. The AC is now solved through other means, but the engine now runs 20 degrees hotter. (200). I pulled the wire connector off the fan solenoid valve on our run down to South Texas this week. So now the fan is supposed to run wide open- well, apparently it did, we averaged about 138 degrees engine temp on the trip down. (And our gas mileage dropped dramatically, so we can't leave it unplugged). So we know its not the power steering pump and its not the radiator. Higher fan speeds cooled the engine to crazy low levels. SO, current thought is one of the sensors that sends voltage to the fan solenoid valve, forcing more fluid to the bypass circuit and slowing the fan. I have seen an 'air inlet fan temp switch', and a 'coolant temp switch' in schematics. Can someone guide me on the exact list of what cuts down the fan speed via the ECM and where each sender is?