intercom wiring

Good point- maybe the unit he has isn't as shown in the diagram I found. Either way, it's not as described. Certainly a set of dry contacts can't drive a door strike, so they're definitely not dry contacts. If they can drive the strike when directly connected, but can't do it with just the red output connected, then it seems the thing to try would be to see what that black output is doing. Possibly just need to connect it to the ground side of the door strike. Then it's the same as a direct connection. If it doesn't work then, there's more going on in there that we'd need to find out about.

Yes when wired individually both systems work. The diagram you show is for a different model of doorfone. I have a DP28 2 button intercom with a built in door strike controller so I dont need the extra box. You may have something there though with the extra relay. Would I need a SPDT or DPDT relay for this? thanks a lot

If the unit will open the lock when connected without the keypad, the relay should not be neccesary.  Hey I have an idea, check for continuity between the common and the normally closed connections of the keypad.  You may have a defective relay or an open trace or a bad connection on the back of the circuit board of the keypad.

Can you make a couple measurements with a meter to see if we can see what it's actually putting out? In your other thread, you indicated if you swap the wire around so that you're running the black wire to the keypad, the door strike is continually energized. This indicates the black output actually has 12V on it continually. The red wire probably is a shunt to ground when the doorfone is active. If this is the case, then you'd just need to change it around to use ground switching for your door strike rather than (+) switching.

I assume you know how to reconfigure it for ground switching, but if not, we could draw it up for you-

Yes the - door contact outputs 12v continually. Sorry I am a novice at this hence so many questions. Can you tell me how to wire it for ground switching with both units connected?

Note I changed the colors of the wires coming out from the door fone, but the terminals should be how you found it originally- The red wire is now the +12V constant, and the black is the switched ground output-

OMG! that's genius. Thanks for the wonderful diagram. I will try it and let you know how it goes. I would have never been able to figure it out on my own, but it makes perfect sense. I'm hopeful about this one

And now you have a customized door lock - Hope it works out!