the last couple of days when i start my truck the grid heater light hasn't been coming on, i have been plugging it in & it seems to start fine. so i am wondering if anyone else has had this problem? it has been -10c (15f) and the truck has 84000kms on it. any help would be appreciated...thanks

 

mine does it to its because it is sensing the engine is warm enough to start so it will not come on.

 

Mine never comes on if it's plugged in. I don't know how it knows whether it's been plugged in or not. Maybe it's coolant temp, maybe it's air temp in the plenum. ??? It does however cycle on and off once it's started.

 

ya i just tried light check and the light works, so then i started her up and the heaters must be cycling because the voltage was dropping as it normaly does

 

Yeah your normal no worries just means your block heater works real well

 

This is correct

 

The intake heater is triggered by intake air temp. The engine heater is raising the air temp. under the hood above 60, so the heater light doesn't come on. If you get a windy night I bet the light will come on.
Ted

 

thanks guys

 

Glad I checked here. I thought I might have to take it in and get it checked. I know my grid heater is working because I get that surging voltage drop that I've read about. I just bought the truck and it's been very cold here so I have kept it plugged in. When I test drove it I never seen it either...(I was looking at the wrong light). The dealer always had it warmed up before I got there.

 

That would be one megawatt block heater you got there if it did that! Intake air temp means temp in the intake manifold, not under the hood.

 

Actually on CR trucks there are two intake air temp sensors. One in conjunction with the MAP sensor in the intake plenum. The other is air inlet temp and it lives out near the air cleaner. The two function along with the coolant temp sensor to feed the ecm data so it can decide how to deploy the grid heaters. If coolant temp is up because the block heater was on, the grid heater may not cycle before starting. Once started if the air inlet temp sensor sees air temps that warrant it, the grid will still cycle.