My 1980 300D won't start all of a sudden.
Been running/starting great all day.
Car starts really easy and fast even in cold weather.

After excluding vacuum issues (to make sure fuel wasn't being cut off)
I went to take all the glow plugs out and test
them, just to be sure they were okay.

This is what seems wierd:

I get 12 volts with key on, at the relay, on the pins for connector.

With all 5 wires off the glow plugs I get 12 volts at each end that
connects to glow plug.

When I connect the 5 ends to the glow plugs, and then connect my volt
meter and turn on the key I get nothing - no voltage with key on at the
glow plug. But I do get 12 volts with the 5 ends disconnected.

I am befuddled. I seem to remember that I used to get voltage at the
glow plugs.

All glow plugs passed the heat up test with 12 volts applied directly.
I do not have an ohm meter that goes below 10 for proper resistance
testing, so I test with full 12 volts off my battery charger.

I know that the glow plug creates heat by resistance, but I still think there
should be 12 volts at the glow plug.

Can anyone please explain ?

Thank you.

__________________
80 300D 340K Owned 30 yrs
83 300SD 440K Owned 9 yrs - Daily Driver 150mi/day
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