Hey all, I've searched as much as I can here about grid heater probs but mine is a little strange. The current temps here in Vancouver, B.C. are around 0-2C (34-36F). The "wait to start" light doesn't wait, it goes out with the rest of the dash indicators after you key on and the grid heaters don't come on. The truck is also VERY hard to start. They DO come on after I start as I can tell they cycle when idling as my power dips and rises like normal, until I start driving. Seeing as they do cycle after the truck starts, I'm assuming my grid heater fuse and relay in the PDC is OK, as are the main grid heater relays underneath the battery. I would also assume the grid heater element itself is ok as it draws the current down after starting. Would this be a sensor problem (IAT)? I can replace it easy, but if anyone has had a similar experience and found the problem, I'd love to hear it. Thanks.
Michael.

 

I can't point you to the problem, but wiring the relays to a toggle switch and controlling them manually is a very easy band-aid till the weather warms.

 

Not really doable for me right now, I'm leaving for out of town for a week and need to leave the truck for my wife to drive.
Anyone?? know anything about this problem?

 

This is just a shot in the dark... (but that what internet forums are for!)

Perhaps you have a bad temp sensor? During normal startup what is the "Wait to Start" light waiting for? Temperature... right? So this would explain why your "Wait to Start" light is shutting down right away in the startup ignition cycle, and it would explain why your truck is hard to start (because the grid heaters have not yet run).

I don't know if the temp sensor would be in use during the cycling of the grid heaters after the truck is started, I think it may be more of a timer based thing not a temp based thing.

So...

Check to see if your grid heater temp sensor if funcitoning properly.

Sean.
Vancouver, BC just got dumped on with snow!
okay, okay, it's only on the local mountains, but it shore looks purdy.

 

Thanks Sean, yeah I'm in White Rock, tried snowing on us a few times today as well. It's interesting, my overhead display temp sometimes shows warmer than actual when I start up but that's from the sensor behind the front grill afaik. The grid heater sensor is actually the IAT on the driver's side rear of the engine block, below the valve cover. That could be one issue. The other thing I found is this was happening in my driveway which is on an incline. I normally park nose up. I backed in today, parked nose down and left it for a few hours. Later I went to start it and it fired right up. I'm away from home right now but the wife's going to try it tomorrow morning and if it starts then, then I've got a leak or a valve back to the tank is shot allowing fuel to drain back into the tank depressurizing the lines. I talked to BD Power in Abbotsford today and the service tech there said they've been seeing more of this since the lower sulfur diesel has been coming out. I'm replacing the IAT anyways but I think it's going to be something with the fuel line ultimately. I'll update when I find out more...

 

Just keep the block heater plugged in for a few hours before you need to leave and it isnt an issue. Truck should fire right up. I use my block heater anytime it goes below freezing and the wiat to start light light goes out when the other indicators on the dash go out and the truck starts right up.

But it does sound like one of the sensors isnt working right.

Good luck with it.

 

The Haynes manual has an excellent section on testing every component in the grid heater system. You'll need a digital volt meter. It'll walk you through the whole process. Good luck.

 

Update, it's actually leaking from around the I.P. somewhere, my wife's just confirmed a diesel leak under the truck. Gonna park it for now, I'll have to investigate when I get home.

 

UPDATE...Hi, it turns out it was my BD Power 5 PSI pressure sensor monitoring my LP pressure. It actually broke internally and was leaking out between the brass mounting base and the electronic housing of the unit. Went and got a new one and all is good. Wasn't my grid heater or relays after all. Amazing what a little air in the system will do to your truck. Thanks for your replies.