Ring Retrofit wired in parallel with DSC Power series

Hello Ring experts,

I got my Ring Retrofit Kit installed and working fine, but I wired the 3 zones on my old alarm (corresponding to the 3 doors I want protected) in parallel to the zones on the Ring Retrofit. The reason I did that is that I wanted my old alarm panel to still function and show the open/closed zones and do the “chirp” when the doors open/close. (I know the Ring Alarm base has that function too, but since it’s installed upstairs I can’t hear it as well…)

In any case… with the Retrofit installed in parallel, the zones on the original panel no longer function… when I open a door, the old panel quickly alerts., but immediately goes back to the “closed” state as if the door has been immediately closed.

I used a multimeter to measure the resistance and voltage across the affected zone with and without the Retrofit installed, and here’s what I observed:

For voltage (measured across the zone; Z1 and C)

Door state | DSC only | DSC + Retrofit |


OPEN | 7.9 V | 2.0 V |

CLOSED | 0 V | 0 V |


For resistance (measured across the zone; Z1 and C):

Door state | DSC only | DSC + Retrofit |


OPEN | OPEN | OPEN |

CLOSED | 0 ohms | 2 ohms |


So with the Retrofit removed, the old alarm works normally… with the Retrofit installed in parallel the zones on the old alarm no longer work properly. I suspect it may have to do with the voltage drop in the OPEN state with the Retrofit installed, but I don’t know for sure.

Anyone know if there’s anything I can do to get the old alarm working in parallel with the Retrofit?

There are no EOL resistors installed on the old alarm…

Thank you!