i was running around today. stopped had lunch. got in the truck, started fine, had defrost on high, fan was about 3/4 power..mabye. looked at the volt meter, it was around 12. drove about 1/4 mile and the fan kicked into high gear. volts went to 15 or so. what do you think? i believe it happened once before. p.s lights were on and wipers going as well.

 

Sounds like maybe just your grid heater cycling. If so, it's comepletely normal.

 

Yup. Sounds like your grid heater kicked in just as you looked at the guage.

 

can the grid heater cycle when the truck is already running? no yellow light, like pre start

 

^^ Yes. Depends on air intake temperature.

 

On 06 they will go for couple minutes or until you pass 20 miles an hour.

 

It does that on my '08 and my '06, and did it with my '03. It's normal.

Glad to see someone else that watches their gauge cluster like a hawk.




Kris

 

i'm just glad i can ask a question and get great responses in little time!!! thanks!

 

Every year about winter someone asks this same question since this site has began . Time to check my antifreeze and winterize the motor home winter is coming . I remember my first diesel , a 91 dodge and the amp gage taking a dive on a cooler fall day , I called the dealer and got the grid heater speech . That truck went through regulators every few years , I always figured it was because of the recycling of the heater .