Hi

My frend have a 07? Yamaha yfz450r and he cannot get it started. When he turns the ignition, no lights in the dash illuminates, or the start motor does not click or turn over. Like the battery is dead. It iz not, cause its measuring 14,5 volts, but it drops quickly, even when the ignition is off. I am thinking if something is shortening, but I dont know where to start looking.

He said that after a heat, he stopped the quad, and when he should start it again, it was completely dead. The only thing thats illuminating is a box with diodes that says "pwr" and "diag" nothing else.

Can anyone help us sorting this out?