I was stopped at a light on my home yesterday. My xjs kinda loud so when it stalled I knew right away. I still had power but not enough for the starter to engage. My battery definitely holds a charge of 12v but drops to 7v when I try to start it. Even on a jump it doesn't start. Any ideas why?

 

After it cooled off,did it start again? Mine did the same thing awhile back,when it cooled off,it started and ran great,till it got hot again. Ended up being the CPS,changed it out,haven't had any more problems.

 

Redid the cooling system the other day, ran fine. That day it was running for like 10 minutes. Cooling off overnight didn't help. I put a new battery in it and it helped for about 5 minutes then did the same thing.