The test points are there, but just not populated, but you can touch your meter to where they are supposed to go. There should be one marked +SENSE (note, not the -SENSE one), and any of the GND test points.
You can also use the bottom (positive) side of the C1 cap (if you are looking at the AR so you can read the text, though they are often mounted upside down in the cab). The positive cap lead gives you an easy place to clip your meter to.
Note you also want to measure the voltages on the game PCB as well, to see how much voltage you are losing in the harness.