SInce the day I bought this truck, when it gets cold and the fuel heater turns, the engine light comes on too.

And Im on my 3rd set of a batteries in a year. They keep going bad. ALOT of acid will collect around the drivers side battery and eventually wont be strong enough to start the truck without a boost.

ANY ideas? The dealership is scratching their head. None if this has cost me a thing...but Im beyond annoyed. Just had to call a tow truck for a boost, cause the batteries they put in 2 months ago werent strong enough to start the truck.

 

I bet your fuel heater somehow stuck on. Have them unplug it and check for a current draw.

 

Where is the fuel heater???

 

I am also unaware of any fuel heater on the trucks. Please explain this to me. I know about the block heater and use it often here in Virginia as last night we got down to 20 degree's.

 

The fuel heater is located in the fuel filter canister.

DESCRIPTION
The fuel heater assembly is located on the side of the fuel filter housing and internal to the fuel filter housing .
The heater/element assembly is equipped with a temperature sensor (thermostat) that senses fuel temperature. This
sensor is attached to the fuel heater/element assembly.
OPERATION
The fuel heater is used to prevent diesel fuel from waxing during cold weather operation.
When the temperature is below 45 ±8 degrees F, the temperature sensor allows current to flow to the heater element
warming the fuel. When the temperature is above 75 ±8 degrees F, the sensor stops current flow to the heater
element.
Battery voltage to operate the fuel heater element is supplied from the ignition switch and through the fuel heater
relay. Also refer to Fuel Heater Relay. The fuel heater element and fuel heater relay are not computer controlled.
The heater element operates on 12 volts, 300 watts at 0 degrees F.

 

Yes only with the key on, same as grid heater.. The wait to start light is the grid heater.