It's a Saturday and my '78 240 won't start. No GP light. I swapped my battery with a new spare, changed the Strip Fuse, and still no go. Checked the GP's and the #1 is reading higher than the rest. It is my understanding that if the #1 fails it won't start, is that correct?

I called every parts store in town and nobody has glow plugs in stock...no one! So...until I can order some from Phil:

1- Can I switch that plug with another one and have it start?

2- Can I use a glow plug out of my wife's '82 300D temporarily? (She's not home)

I can't believe nobody has them in stock. Is this common?