Thanks for the info. My only other diesel was an 81'
Rabbit (good car) and the glow plug light only came
on when it was not hot. I think it would result in
a shorter glow plug life if they were energized every
turn of the key rather than just the initial cold start.
Anyway, I was looking for an old thread and came
upon another on page 4:"Strange plugs which are
interspersed with glow plugs." and according to
one guy there is a temp sensor for the glow plugs.
The car in question was an 81' 240d, mabee this is
not on all models. Good luck with the plugs/relay.