Boxerworks.com

Hi,
I recently bought my first air head and am new to the forum. The bike rode great with no issues for 300 miles until I tried to start it yesterday for another warm day in Northern NJ.
When I pushed the key in it turned over for a split second and then died. Now only the orange light comes on and nothing happens when I press the starter button.
The battery was in a tender and has 13.4 volts. Where do I start? Thanks .

What does the voltage across the battery terminals read when you push the start button? If the voltage drops well below 10v, your battery is toast regardless of what the tender was saying.

As an emergency, you should be able to kick the bike to start. The kicker is just that, mostly for emergencies...the internals aren't all that great.

Kurt

Thanks for your reply.
12.47 volts without the tender.
As soon as I push the key in it drops to 12.11.
Nothing happens when I push the starter- no buzz, no crank, no nothing!

Well, trying to kick start it woke something up!
Orange light went out and red light came on.
Pushed the starter and she started up.
Any ideas. Battery, coils?

First thing I'd look into would be the starter relay. If the terminals of the relay get corroded, the relay won't latch and the starter won't turn. The relay usually resides along the left side of the top frame tube underneath the tank. Maybe an inch-square cube?? Try pulling the relay up and re-engage a few times...that might help clean up the terminals.

Kurt

Thanks, I’ll try that. Went for a quick ride and the battery had 12.92 volts when I got back.

Apolis61+ wrote: ↑Sat Nov 09, 2024 4:33 pm Thanks for your reply.
12.47 volts without the tender.
As soon as I push the key in it drops to 12.11.
Nothing happens when I push the starter- no buzz, no crank, no nothing!

The fact that the voltage only dropped to 12.11 volts is an indication that the starter wasn't being connected to the battery otherwise it would have dropped much further whether the starter turned or not. So as already said it's likely to be in the starter connection circuit possibly the solenoid.

Have a read through this https://brook.reams.me/bmw-airhead-moto ... er_Circuit

The thing to be listening for is a click... in fact two clicks, one of which can be better refered to as a loud clack when the button is pressed.

The clack is the starter solenoid slamming home and engaging the starter pinion as well as completeing the circuit between the battery and the starter.

The 'click' is the starter relay closing to energise the solenoid.

If you hear nothing, then the chances are good that the problem is with the starter relay, the button or the wiring surrounding them.

If you hear a 'click' but no 'clack' then the problem could still be the starter relay or the wiring to the solenoid or the solenoid itself.

Probably the first place to check is the contacts at the starter relay. These have a habit of becoming corroded or dirty and cauing this sort of problem....

Good luck

Rob

Thank you all for the help and for the link.
Very informative! Looks like I’ll be pulling the tank soon, cleaning contacts and listening for clickety clacks!
Angelo

Your original description of the issue made me think of a loose/dirty battery cable at the battery. Might give that a clean while your in there.

Had a truck that would make one click and then no power anywhere. Twist the battery cable connector on the battery and back to life. The cable would essentially arc to the battery terminal and cause it to not have a good connection. Finally replaced the cable with one with a better clamp.

Good luck!
Tom