I know theres a preheat in the intake but doesnt it just start at start up? or after truck is running does it cycle on and off? Because some mornings when i start it i notice that even after a few minutes of idling my interior lights flicker (dim off and on) and my voltage drops from 14.5 to about 12 or so. sometimes when i drive off with a warmed up engine it does this too 9especially if cold outside) iis this normal?

 

mine does it too its the grid heater cycling it will do it when its cold me living in alaska where its cold all the time. mine does it almost everytime i start it

 

Normal, grid heater draws 24 volts

 

Those heaters draw alot of amps,if you watch its enough to dim the headlights too

 

ok should it do it when engine is warm? (cold outside) or just at start up?

 

mine will do it for about 5 to 10 mins when i first start it on a real cold morning it dosent do it when im driving down the road just at start up it will even do it when the motor is warm and i start it but it will only cycle about 3 or 4 times

 

Ummm, I'm pretty sure the truck has a 12 volt system, but requires two batteries to handle the amperage of the heater grid. Can someone confirm?

 

I was thinking the same thing......I know there is a sticker in the engine compartment that says "only connect 12v when charging or jumping the batteries" (well maybe not those exact words....but something along those lines).

 

It's definately a 12 volt system. Nothing 24 on these trucks

 

lol all 12 volts...