Answer. DaveJM on February 02, 2021. "10" is what I would assume to be 10 volts. "14" sounds like 14 volts. Why don't you start by ensuring a known good battery is installed in the vehicle. Do that first before continuing to tap starter motors and do other testing. Sometimes cars won't respond to jump starting that well, and 10 volts is ...
If your starter easily cranks a cold engine, but "drags" or cranks very slowly when hot, there may be a "heat soak" problem. Before you condemn the starter as bad, you should perform a system diagnosis of the battery, cables and starter.