14′ Turns over won’t start

OK so I was called by my mechanic who had my bike in under a warranty repair, it was running fine before as far as starting and never had an issue. Now he says its not getting complete voltage (12 v) to fuel pump. Turns over just fine and when he jumps out the fuel pump it will start and run.

its been sitting at his shop for almost 1.5 months due to part on back order and we all know how things go wrong with a ATV just sitting there and not being started and used. Could this possible be a corroded ground wire somewhere and if so where?

I have not picked it up yet (just got the call a few min ago) but when I do I will look more into this and just wanted to get some ideals ahead of time.

Thanks,