Electrical Guru's needed!

[whitestang41791]

Hey guys, hoping for some feedback on a problem im having with my 2003 750.

Long story short, i had the battery on a tender all winter. Unhooked the tender and a couple of days later went to start the bike. Stone dead. Recharged the battery out of the bike and had it loaded tested. Passed. I found this unusual, so when i put the battery back in, i hooked a multi meter to it.

As soon as you turn the key to on, the battery begins to rapidly drop. It dropped from 12.5 to 7.5 within roughly 45 seconds.

I tried both my wave runner batteries directly connected to the bike.. same result

Tried my car battery.. same result

With testing so many batteries, i am comfortable ruling that out.
Keep in mind the battery discharges even while the bike is running @ 2500k RPM.

Im a mechanical engineer by trade, but electrical seems to always beat me. Any feedback is appreciated

[92xjunker]

Measure the amp load, disconnect the pos batter lead, put a meter set on D.C. amp between the battery post and the cable. It may be the alternator drawing that power as anything else would most likely burn.

[whitestang41791]

"put a meter set on D.C. amp between the battery post and the cable."

The cable from the alternator? What should i be expecting.

[92xjunker]

Battery cable. What is the draw? Once you get the draw, unplug the alternator. Now what is the draw? Just some help with some high amp draw finding techniques you can use.

[whitestang41791]

ok, update. linked the issue to the headlight assembly. when you disconnect the wire harness behind the little cover above the headlight, there is no rapid draw. When you reconnect AND remove the headlight bulbs there is no draw. Once you put the headlight bulbs back in, the massive draw is back.

Maybe a relay?

[Kreylyn]

ok, update. linked the issue to the headlight assembly. when you disconnect the wire harness behind the little cover above the headlight, there is no rapid draw. When you reconnect AND remove the headlight bulbs there is no draw. Once you put the headlight bulbs back in, the massive draw is back.

Maybe a relay?

More likely a burn wire or connector. I'd trade the entire headlight harness for the issue.

No relay on your model that I'm aware of for the head light. It's on with switch, hi / lo switch.

Krey