If you remove the connector from the motor (the connector pulls apart -- carefully!) and wire the motor directly to the battery, you should be able to hear the motor running (polarity doesn't matter for this test only). If you get sparks but no sound, the motor is frozen. If you get no sparks and no sound, the internal wiring is open.

If the motor runs, the problem is likely the ACC, as has been said, or the monovalve. Both are repairable or replaceable. Lots of information here, do a search for "acc" and/or "monovalve."

__________________

"Buster" in the '95

Our all-Diesel family
1996 E300D (W210) . .338,000 miles Wife's car
2005 E320 CDI . . 113,000 miles My car
Santa Rosa population 176,762 (2022)
Total. . . . . . . . . . . . 627,762
"Oh lord won't you buy me a Mercedes Benz."
-- Janis Joplin, October 1, 1970