Flickering Glow Plug Indicator
 

Search was inconclusive. Car's an 83 300D, 190K.
My glow plug indicator is starting to flicker once in a while, most noticible in the morning. Car starts fine. Can't tell if the flicker is from wiggling the key or not. Does the glow plug lamp indicate any type of GP health in this car? Would a getting ready to fail relay do this? Car started this morn at 14F without block heater so I am thinking the GPs are pretty much OK.
Thanks for any and all advise.

It could be that the relay is becoming intermittant. You can pull it and clean the contacts. The metal cover is removable. If you have series loop plugs like mine, then now would be a good time to clean the linking wire connections with a fine emory cloth. I have had a couple of failed glow-sessions this month, and finally discovered that one of my fairly new loop style plugs (Bosch - made in India - high in the Bavarian Alps) had an intermittant crimp on the tip and I had to replace it. The plug tested open on the bench until I torqued the tip a bit with a flat pliers. Then it tested ok.
Anyway - food for thought.