The main cooler is designed to regulate the trans fluid temp, essentially around engine operating temps. If towing etc, the auxiliary cooler helps get rid of the excess heat. Simply unplugging the TCC solenoid will not overheat the trans contrary to what many people think/say. Yes it will run at a higher temp but essentially it's a heat energy loss, fuel mileage decrease. You'll be fine with it unplugged while you figure it out.