Just an FYI.
Some years back I bench checked a few factory IVR's using my Fluke 179. It has a ability to average readings over time.
The voltage output of the "point style" IVR will start at 12 volts when first powered up then it will go to 0 volts when the points open. The points close again and the it's output goes back to 12 volts. With in a second or two the points will be opening and closing at a very rapid pace. Way too fast for the meter to read in real time.
I switched the meter setting to average reading over time and found that the IVR was outputting and average voltage of around 4 volts. I was a little surprised that it was not closer to 6 volts. I tested the other IVR's using the same method and found the same results.