Yes I am working on a 06 dodge cummins and it was having a hard time starting bought new batteries fixed problem. Tell weather hit -24 then fuel gelled up and replaced filter it started fine next day and know even if it's ran for a hour if your turn it off it won't start without ether and I told the guy it's really bad to start with ether

 

Heater grid working? Fuel heater working?

 

Not sure best way to test them out the coil light is on but isn't popping any codes

 

Moved over to the smelly forum. Hopefully these guys can help give you a better answer.

 

Smelley forum?????????????????

 

Does the heater grid light go out? Should be able to hear the relays cycling.

 

No just stays on constantly

 

Sounds like either the grid or relay is bad. May need to check for power in and out of the relay. Check fuses first