I have two old touchtone telephones probably from the 60s or 70's that have the old wire with the big old 4 prong wall plug (looks like a European electric plugs). How do I put a new current day wire that has the small clear plug on these phones? I already tried to connect three of the colored wires of the new wire where the same colored wires of the old wire were (there was no place for the black wire). I get a dial tone but when I push buttons on the phone it gives a tone sound but will not dial, it just continues to give a dial tone. I have tried both phones and both do the same thing, so I know it is not the phones. I am sure this is simple but I cannot seem to figure it out and hate to discard the phones. Please let me know what I am doing wrong. Oh, I also have AT&T digital phone line in my house, would this have anything to do with my problem? However, AT&T did say that I could use any of my current phones on this system. Thanks for your help.

If you are getting dial tone and won't dial, swap the wires on the jack, If you hook a Meter to the red and green on the Jack, the Red should be negative with respect to the Green. About 48 volts DC, On hook.