'79 Benz 300D, I changed glow plugs, but now won't start and dash light not on. What is wrong here?

Question

I put some new glow plugs in my '79 Benz 300d. The old ones had a rod going into the engine that heats up. The new ones has a curved wire that heats up. The new ones installed fine, but now car wont start and dash light, for plugs, doesnt light up. Are these the wrong plugs?? What to do now?

Answer 1

Wrong glow plugs you installed.Someone had already upgraded to pencil type plugs.

Answer 2

Did they work before?

There is a fuse in the glow plug circuit. It's located on the firewall, behind the engine. Looks like a black plastic box, about two inches by one. If you open it, you should see a strip of lead inside.  If this is broken, no glow plugs. You can get replacement strips from Mercedes dealers.