Battery voltage should be around 12.5 (fully charged)
After that check that you have minimal resistance between the negative terminal on the starter and any ground point on the vehicle chassis. Set your multi meter in continuity test mode and touch the two leads together. A continuous beep indicates you are in the correct position on the meter. Use this position to test for continuity between the negative terminal and a chosen ground point. If you can't get a good ground near by the starter run a wire from the negative battery terminal to where you are working and touch the other lead on the new wire. Post your results.