Tuesday, July 24, 2007

Note to self: it's the battery stupid!

Two weeks ago my Vulcan crapped out 320 miles from home on the return leg from a PGR mission in Utah. One moment I was cruising along at 75 mph, the next my engine went completely dead. No lights, no dash, no starter.

Yanked in the clutch and coasted to a stop on the shoulder.

Tried to start it again . . . no power. Nada. Wait for 20 minutes, turn the key, the dash lights up -- but when I press the starter a funny sound from deep inside goes "clunk" and everything dies. 45 seconds later the dash comes back to life all by itself. Repeat, rinse, same result.

Two bikers stopped to lend assistance. We mucked around with wires, connectors, checked the safety interlock switches (all three of them - clutch, stand and upright detector).

One of us had a small multimeter in the pack. Battery showed 12.8 volts - about optimal according to my manual. No shorts, no opens anywhere on the circuit.

End up waiting at a small town named Silt, CO for my partner to arrive with the trailer -- a 4.5 hour drive. We load it up and go home.

IN the garage I start tracing things out with my Fluke. Started at the alternator (thinking it had fried), checked the regulator/rectifiers, and ended up checking darn near every wire, cable, component, switch, relay and fuse on the system. Everything checked out.

Battery gets a fresh charge, try again - same symptom as above.

I finally decided to spring for a new battery . . . filled it up, charged it last night and . . . everything works! Charging circuit is fine, I am getting 12.8 volts on the new battery at rest, and it's charging fine at 14.1 volts @ 1800 rpm and up.

Funny thing, the old battery still shows 12.8 volts right now, but it's definitely gone bad. And on this Vulcan Classic Fi - it killed the bike even while running. Odd that.