1986 300SDL Glow Plug dash Board Light
I have a 1986 300SDL that is very difficult to stat in the morning due to a problem with the Glow plug system. I was told that the problem was due to a failed glow plug relay - which I had replaced to no avail. The glow plug light does not come "ON" when the ignition switch is first turned "ON". I reviewed this with the mechanic and he showed me that the light was good and that voltage was being applied to the glow plugs.
Despite this fact, the dashboard light that indicates glow plug activity does not illuminate. Exactly what does the light measure when the engine is first turned on?
Any suggestions as to what the problem might be and how to fix it?