Battery voltage drops to almost nothing with ign on

[D.e.e.]

Hi guys, hopefully someone has seen this before.  Bike h as s been running great for 600 miles after restoration. This morning the neutral and oil light weren't on. Bike wouldn't start. Battery has full charge 13v. Turn ignition on and voltage drops to. 2v. Removed all but main fuse and dropped to 2v. It does have Dyna ignition. I'm thinking a short for sure but any common area to look first?

[D.e.e.]

It is a rd400

[1976RD400C]

That's kind of a odd problem. A good battery would pop the main fuse if there was a short somewhere, not drop to 2 volts. I would start by testing the battery. Charge it. Maybe leave the charger right on it and turn the key on with just the main fuse in and see what happens.

[D.e.e.]

Thank you. Looks like a bad battery.  Odd that it happened overnight and kept goin GB back to 13v. Jumped it and everything is working.

[Barrie]

check your grounding/earthing points and the ignition switch is in good order.