Hey folks -- still trying to sort out my 71 220D (build date 11/71). I cann't find a glow plug relay anywhere, though the wirinf diagram in the Mercedes chassis manual insists there is one. Someone here then suggested that I look for a "fuse on the firewall." I can't find either!
Anyway, I get no power to plugs at all with the start knob in the glow position. Nor will the starter turn when the knob is pulled all the way out (starter tests fine), so I assume the starter lockout switch may be bad or not completing the circuit or whatever reason. Shift linkage IS loose, so I may not be getting all the way into park.
Which leads me to wonder: will the plugs glow with the car in gear? Or does the starter cutout effect them too?
Thanks in advance for any help; I'm pulling my hair out here!