Something ate my glow plug controller.. not literally.. but you get the point.

[trucknorris]

I've been fighting my glow plug controller by having to cycle the key on and off to get some juice to the glow plugs. Whatever ate the GP Controller also took out my WTS light.
Today I replaced the GP Controller with AutoZone Delco unit ($85); (it used to be $59 several weeks ago... doh)...
I am finally getting some good juice to the GP, but WTS light is still dead... Tomorrow I am going to have to crack the dashboard open to make sure it didn't rattle loose.

 

[79jasper]

Not sure what year you have, but if it's an obs truck, clean the bulb and plug connections.

IIRC, it's the blue wire at the controller that runs the light, you could feed it power to see if the light comes on.