Any way to make the grid heaters cycle, even when it thinks the motor is too warm? Went out last night, after the truck sat for about 3 hours in -10C weather, heaters didn't cycle on. It started harder, and rougher than it does after sitting out all night and the heaters cycle normally. Truck wasn't plugged in, was up to operating temp for sometime before I shut it down. Heaters run normal all the other times. Is this just something I need to learn to live with, when its not cold, but not warm either? Thanks.

 

heaters should have come on, heaters are activated with intake air temp.

they are not working right.

 

Sound like to me a IAT sensor that is going south... Or a grid relay... Those are basically the only parts of a heater system...