MikeM

Bike is a 99 superhawk, the wiring is pretty much the same setup as a 900 or an f3.

Problem - there is a (kinda) short in the system somewhere. Battery voltage around 12, but when I turn the key to on, the voltage drops to just under 2 volts. If I leave the key on for a few minutes the battery starts to get hot, so Im pretty sure somethings shorting out.
I tried disconnecting all lighting, the ecu, all relays, and pretty much everything and I think Ive got it narrowed down to the ignition up front. Maybe it has that diode that goes bad.

He did ride in the rain the other day, and this happened the next time he rode it. Im thinking maybe water got in the key hole, then oxidized something inside when it dried.

Any ideas?

NINER

Check the starter circuit. To cause that ibg of a voltage drop and to get the battery warm, it has to be a circuit thathas a large curent draw. I know on cars they have a starter solenoid so the wires going through the ignition are low current. I know you understand the concept of a sloenoid being a switch so I'll save that. Starter is the only high draw circuit I can think of.

MikeM

thats a good possibility

NINER

check it out and let me know.

martino

seems weird something can cause that much of a voltage drop and not burn something out.
you try jumping it?

MikeM

Last night we changed out the starter, starter solenoid, and the ignition switch from my spare parts stash. Nothing fixxed the problem, but changing the starter gave us a weird result.
Key off - 12v at teh battery
As soon as i turn the key on, voltage drops now to 5v, then it slowly climbs up to 9.8 volts (over about a minute) and stays there.
If i hit the starter button the voltage instantly drops to 2 volts, then slowly climbs up to 9 again.

Time to take it to the shop.

martino

i dunno man it sorta sounds like a bad battery

i know your a good mechanic mike, but you do know a stone dead battery will still hold a surface charge of 12 volts or more