V-1504 Enclosed lift

Intermittently the cabin will rise to second floor ,but the door does not unlock at 2nd level. Not certain what circuits to test first, second...
Any help is appreciaited.

Should be the roller switch when it comes to the floor to bring in door zone.

You need to find a mid test point to determine where the failure is. In this case I'd check the power to the lock at the terminal strip in the controller. If it's hot you know the issues on the lock side, if not it's on the other side of your test point.

Best guess though if it's stopping at the floor, I'd be leaning towards it's going to be a lock issue.

What vintage, relay logic or printed circuit board?

Possibly z3a z3b switch, at least this is the problem I had awhile back with one of these. It wouldn't open the door.

Thanks for all the input. I will check all and let you know what comes of it.
I have replaced the center upper roller switch when i was having a similar 2nd floor challenge where it would not even go down let alone open the door. I have extra switches.

The unit has 24 relays

RonJob:
do you have prints oer do you need them? /On the relay logic units, the electric strike was activated by both the door zone rely The electric strike was activated by the electric timer , the door zone relay (via the door zone limit) and the floor zone relay (Z1. Z2. Z3 ) (via the landing limit) These units were pretty bullet proff, so I'd measure for voltage at the stike , but i'd bet a bad strike.

If it is a stand alone 1504, it could also be the tower or the door moved a bit and the pin from the lock was getting stuck against the frame and wouldn't retract. Lowoil is also right about the switches.