Dover hydro with Ibm relays.

Car runs but doors wont open.I have 300dc at Da1 and Da2.

Open Armature, bad brushes ????

300VDC relative to what?? each other (answer above) referenced to negative on rectifier?? referenced to Positive on rectifier?? Do you have a door operator print??

I had this once on a DMC. . It was bad capacitor under door controller But it was intermittent

If you are reading 300vdc between DA1 and DA2, then motor armature is open, probably the motor brushes

Yes. I have a faded door operator prints. If i open the door with operator de energized. When its energized it will close it. Bad re

I would look at the capacitors that are paralleled around the contacts on the open and close relays. One of them is most likely shorted.