glow plug light

[chevy79k5]

ok heres the deal i got a 86 m1009. when i got the truck 2 weeks ago the glow plug light on the dash worked fine. now it dosenot come on. so i know the truck needed glow plugs so i replayced them all and still got no light. any ideas of what it may be would be grate thanks Ryan. (this is my first cucv and diesel so bar with me thanks)

 

[84cucv1ton]

could be the light bulb in the dash too.

 

[Broncoman]

Does the water in fuel light still work, and i guess the truck starts ok? Mine done this about a week or two after i brought it home and to find out it was blowing the 20 amp fuse that controlled the GP, WIF light and such, after tracing it down I found the connector for the high idle switch had come off and got against the exhaust and burnt a hole in the insulation, thus causing the circuit to short and blow the fuse. But if everything else works my guess would be the bulb too.