Hello all, new owner of a '69 220D barn find here. The glow circuit on the car was not operating at all through the switch, and I went through the troubleshooting procedure in the manual and found no continuity through the switch in the glow position, and no voltage at all on the output terminal in the glow position. The starter is new, but doesn't always engage from the switch. This car sat for many years, and I'm thinking corrosion has taken its toll on the switch electrics.

Jumping the circuit to the glow plugs brings the salt shaker indicator to life, so the glow circuit itself should be working. This leaves our switch as the problem. Trouble is, it's not exactly obvious how to replace it.

The pull cable that goes to the injection pump is the tough part, how does it disconnect from the switch?

Any help would be much appreciated!

the switch will operate the glow plug when you pull halfway
between "up" (on) position and crank (fully pull)

just pull from "down " to "up" is not connect to glow plug circuit

you will notice the alternator light dimming during pulling to glow
the glow plug
(wait around 15-20 sec to see light in salt shaker indicator
before fully pull to crank)

normally it's rarely fail
mine is breaking plastic knob from living in hot tropical climate

sorry for my poor english
hope you understand what i wrote

also there is some rubber isolation material in linkage which can go south leaving not enough pull to activate the switch. check it down on the side of the steering column.

__________________
[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

Thanks all. I do understand the proper operation of the switch, with four positions. (Stop, glow, run, start) Glow never works using the switch, start works maybe 50% of the time. This is a car that sat for 30 years.

Trusting that my multimeter and diagnosis from the service manual is correct, has anyone ever replaced one of these?

intermittant behavior also suggests linkage issues.

__________________
[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

The behavior of the switch is the same whether it is in the dash, or partially removed as it is now through the instrument cluster space.

Well, the job is done! Turns out, the cable is held in by a C-clamp of sorts, with an attached peg that goes through the end of the cable. It's nearly impossible to see until you pull the switch out.

That said, ye olde 220D glows and starts like a champ! First start in over a week since I started disassembly and it took less than a second of cranking after the glow before it caught.

Turns out, when I pulled the old switch out of the dash, the glow circuit would only activate with the starter running. The tactile feel of the switch positions is very different between the old and new, makes me wonder if something inside the old one is bent and the contacts are not engaging when they're supposed to.

Mission accomplished!

cool!

congratulations!

__________________
[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.