I went out yesterday (it was cold enough for the heater to come on) and it was like a dead battery. I jumped it and went on my way. it started fine after that, and the next few days( but the heater was not calling as I did not start it early in the AM). So I read the codes and its P0542 Air Heater A Circuit High the batteries read good so I'm assuming its either the solenoid or heater. I see the Solenoid has a hairline crack in it. As far as I know though it (the solenoid) should either work or not? Guess it could be grounding? Can anyone tell me how to read the Heater? Would reading ohms between the poles do it? Also If it is the Solenoid, it looks like any other plan old solenoid that I can pick up for $20. The "official" replacement part is $70. I assume its because its mounted on that "AHEM" special bracket? Any input on that? I'm in Palm Springs so as long as I dont start it early in the AM Im good to go but longer term want to solve this.

 

but the heater was not calling as I did not start it early in the AM). >??????????????????????

 

I was trying to say that on the subsequent days I did not start the truck in the early mornings. here in Palm Springs the early AM can be 40 but by 10 AM its 70 so the heater is not calling to be on at 70 outside air temp

 

my truck will start at 30 degrees without the heater with no problem