4720 Glow Plug Indicator Display Light Doesn't Work

[jcalla]

Preheater works but indicator light doesn't. Last six S#770631. Any ideas?

 

[beenthere]

Why start a new thread when this seems related to the other thread on this problem?
https://www.tractorbynet.com/forums/john-deere-owning-operating/407882-tm2370cd-serial-770631-a.html

Maybe check some voltages against the electrical diagrams furnished would help to see if a bulb (?) is burned out on the circuit board or not getting energized?

 

[jcalla]

Bulb is fine. Lights up when you turn the key on.