I never knew repainting the frame and engine were bad for the bike..........

[BubbaZanetti]

so here's the (quick) story:

this weekend i decided to do a partial tear down and paint job on my bikes frame and engine where it had become unsightly and a little rusty. to do this i took off the gas tank, the coils and disassembled the rear of the frame (shocks, seat cradle, rear fender) and in doing so disconnected the wires for the rear lights/signals, rear brake and i'm guessing neutral indicator (left side)


mind you, these were the only electrical connections i disturbed

so i finished the job, put the bike all back together, being very careful to do it exactly the way it was (i had even labeled the wires on the coils) and i installed a new battery (a "big crank" powersports/atv sealed battery that while not being specifically designed for bmw's had the right dimensions and power) i turned the key and heard a few little clicks from the relay under the ignition and nothing, no lights, no ignition, nothing at all. so my question is: could the battery have blown something, is there a dead connection somewhere and i'm just not completing the circuit? i know you can't see my bike but i was wondering if any of you had ever heard of a battery being "too powerful" or what these symptoms might indicate.........

this bike sat outside for a long time and has had little electrical "demons" before, but is generally great if i use it everyday, this was my first 3 days without riding all summer

sorry if this was a little long winded, and thanks

[YB in IN]

Have you done a voltmeter test on the new battery? It may be bad. Do you have the old battery laying about that you could connect to see if that is the problem, or is it dead and long gone? That would be where I would start. Good luck. Electrical problems can really really suck.

[James.A]

Garth is right, a good, fully charged battery is the very first thing to confirm when you have electrical trouble. You will also need a volt/ohm tester and a wiring diagram for your bike. When fiddling with airhead electrics, it is important that the battery negative cable be the first one pulled and the last one re-connected. This is the safest way to de-energize and re-energize your electrical system. Arcing when disconnecting the battery + cable can damage sensitive components. You should check your fuses. I'm not sure where they would be on a 1984 R100. On earlier bikes, they are in the headlight shell. When you have your wiring diagram, familiarize yourself with the wire color legend and make sure every wire you pulled is connected where it is supposed to be. Use the ohm function of the test meter to test your wiring, by the color codes, point to point. Be patient and good luck. Ask plenty of questions. We're here for you.

[Cosmoline52]

Maybe this is a little obvious, but if the battery isn't application-specific, is the polarity correct? Ground cable secure?

As mentioned new batteries sometimes need a trickle charge to bring them up even when the salesperson says they're fully charged... could also be that if your bike is a little "weathered" the cables could be corroded so replacement might be necessary, and the corrosion might be within and not so apparent.

Good luck, electrical problems are always a learning experience!

[BubbaZanetti]

well, thanks for the input guys, i found it, bad connection at the starter relay, a little wiggling and some dielectric grease cleared it up, great to have it running again.............

[Bobmws]

Glad you found your current problem. While things are apart I would clean all the electrical connections. Also replace the main positive lead to the starter as well as the main ground cable, they very likely have significant internal corrosion that will cause some of your electrical gremlins. An additional ground to the frame is a good idea too. These are things I found on my R90S as it reached the 20m year mark. HTH