Hello everyone, new user here. I hope I'm posting this in the correct forum.

I'm trying to wire a Teledex Diamond to a POTS telephone line instead of a PBX. When I plug the phone in, it rings continuously and does not make or receive calls.

Is there any way to wire it in such a way that it can work on a regular telephone line? Also, is this typical behavior for this type of phone?

This is likely a hotel/motel phone. If so, there's likely a hidden switch that allows you to select between a PBX line and a standard line. If you find it, just switch it to the other position. If there's not one, it's probably a custom unit that rings on 48 volts DC. If that's the case, there's nothing you can do since it's not meant to be directly-connected to the regular network.

Not trying to second-guess my esteemed colleague Ed, but...

Their website states that they have sold "millions" of these telephones. All the copy implies that these are plain old telephones, usable on all the PBX's in the world. I can't think of a single PBX that rings on 48 Vdc. Have you Googled the user manual? It says that the phone has a REN. That would imply that it is compatible with the PSTN. Does the phone have a red message Waiting lamp? Does that lamp illuminate steadily while the phone is ringing steadily?

My prognosis: You have acquired a defective telephone. Did you perhaps find it in a dusty telephone room at some motel, and it jumped into your car when no one was looking? Probably it was defective long before you...ahem...liberated it.

They made some models that worked on Comdial and Hitachi hotel/motel systems that used low voltage ringing, but I can't remember the actual specifications for them since they weren't in very high demand. WECO's Horizon also had a hotel/motel package that used the second pair for ringing. Teledex was/is the name in OEM phones for the hospitality industry, so I'm sure that anything is possible. I have to agree about the REN part though. That's usually a dead giveaway.

We had hotel customers that had some of these phones. Some of their models had programmable buttons for room service, front desk and such. All of the switches for everything were hidden under the face plates of the phone. One model I recall had to have a switch position changed to program buttons. You may have a similar situation.