Glow plug light won't go out...

[1949gmc]

I plugged in my truck for the first time last week and when I did, I could hear the block heater 'turn on'. It worked like this for the next few times, then one morning the glow plug light wouldn't go out and it was hard to start- glow plugs don't seem to be coming on. When I plugged it in that night, I did not hear the block heater turn on like I had before. Is the glow plug deal related to the block heater? Can anyone tell me what the deal is with the glow plugs? Fuse, breaker, relay? It's an '04 LLY Silverado and I don't like the idea of taking it back to my dealer-don't think they have much diesel experience. Any help would be greatly appreciated.

[More Power]

The glow plugs are relay controlled. Having them on all the time is not good.....

Try disconnecting the batteries for a few minutes. This should reset any DTC codes, and could get the various systems back to normal. If not, you'll need to visit the dealer.

If you have a way to read codes, you could look at the related LLY glow system trouble codes listed in the article on the LLY (http://www.thedieselpage.com/duramax/lly2004.htm) to learn more.

If the engine runs more or less normally with the glow plug light on, you should also be getting a service engine light, indicating a problem with the glow system.

MP

[1949gmc]

MP,
Thanks for your help. I disconnected the batteries this morning for about five minutes, but after I got to work, so now it will have to get cold before I can see if it's fixed.
To clarify, the light goes out after the truck starts, but stays on before starting. Usually the light comes on for a few seconds, goes out, then I start the truck. Now, the light comes on, but won't go out until the truck is started. Also the block heater is working fine. I've had it plugged in the last few nights just so that it will start easier in the AM, but it's only been about 28-30 degrees. I shouldn't have to plug in at that temp.

[B1powered]

How long have you waited before starting it?

Cold weather will have longer glow times.