Hello Jim H
Living where you do; you get plenty of practice checking your glow plugs.
I have checked mine twice this year, found a bad one each time.
Quality of parts seems to be an issue the last couple of years.
I will be ordering spares this month.

Hi whunter,

Well, it's not really cold, was 40-ish. The 5" of snow Wednesday made it more interesting, though... It turned my 3 hour drive home from Detroit into a 5 hour drive, since I went through the heart of it.

The SDL never missed a beat, but the windshield wipers and body trim like to interfere with each other when the wipers get iced over.

For the good of the group, my experience...

The glow plug indicator failed to light one day. I checked, using the method I described, and found #4 read Open. BTW, I did this check in the parking lot at the job site between meetings, so it really is quick and easy.

The next time I started the engine, the glow lamp worked. My bad, I assumed a miracle cure.

The glow indicator worked fine for each start for the next 3-4 weeks, then stopped again. That time, I tested and found #4 and #6 were Open.

Moral of the story

The glow indicator may work fine with one 'bad' plug, as others have said on this forum.

If there are starting 'issues' do the ohmeter test, it will find Open plugs. It may, or may not find marginal plugs, but it will find an open plug.

Best Regards,
Jim

P.S. Glow plug removal on the OM603 was not nearly the struggle I was anticipating.