Drawing Number 1-A257501C Circa 1967. Will run on inspect, if on auto if opens fuse 4. Have looked for the obvious coils that may be shorted. We have removed the feed to the door operator, to the hall and car call circuits. It appears to be a coil in the auto circuit. Have pulled all the wires on C65 and found the one that opens the fuse. It is a controller wire and it is grey just like all the others. However, with that one wire off, nothing will energize and we will not run on inspect. Going broke trouble shooting this. Looking for any ideas, to help find the culprit.

Was the cartop inspection station added later, and if so, are your prints marked up to show the changes?

I had a similar problem can't remember what fuses it was blowing but was the feed to the door operator. It ended up being a bad phase 1 key switch. Switch shorted internally

Went to update this and see that I did not title it correctly. Who ever heard of a 10-21-20 UCLs...Geez 10-21-30 UCLS

The door would open and close partially before the fuse would open, so we did not think that was the issue. It was, removed the wires going to the door armature and the field, she runs fine on auto now.

Will send that motor out for rewinding.

Good find.thanks for the update