New owner R65LS and BMWMOA member - Battery Issues

[glane]

Hi BMW guys and gals: Just picked up a 1981 R65LS. Back into motorcycling after a 20 year hiatus. Does anybody know whats going on with the lack of battery charging? I have a stray wiring harness plug where the battery tray is located. Do you think this was for a trickle charger? Thanks in advance for the assistance.

 

[20774]

Welcome to the forum, glane! I took the opportunity to move your post out of the other thread. This way, your issues will get more focused eyeballs. Plus I added a bit of context to your title.

So, with no battery charging, the first thing I'd ask is the status of the lights on the instrument pod. I think it's the same on the R65LS as other Airheads. But when you turn on the ignition but don't start the bike, do you have a red light for the charge indicator? If not, that could be a problem. Secondly, once the bike is started, does the red light go out when the RPM gets above say 1500? Also, a problem if that doesn't happen. For the first situation, if you have no red light initially, then it's possible that the bulb for that is burned out. The Airhead charging system is funny in its setup...there must be working bulb in the circuit for the charger to work.

The next easy step is to measure the voltages at the battery terminals with the bike running at say 3000 RPM. Do that and report back. It should be well north of 13v, even near 14v. Then we can go from there.

 

[glane]

75/5 Vs. R65

I put 80 K miles on a 75/5 back in the day. Great bike except for the front drum brakes when it rains. Hopefully my R65 with dual front discs is a little less sketchy. By the By I just paid 3K for mine with two thousand original miles, but it has a bunch of deferred issues. I think I'll like the R65LS as I am older and a little bit short at 5" 8" so the lighter weight and seat height works for me.

 

[glane]

R65 Carging issues

Welcome to the forum, glane! I took the opportunity to move your post out of the other thread. This way, your issues will get more focused eyeballs. Plus I added a bit of context to your title.

So, with no battery charging, the first thing I'd ask is the status of the lights on the instrument pod. I think it's the same on the R65LS as other Airheads. But when you turn on the ignition but don't start the bike, do you have a red light for the charge indicator? If not, that could be a problem. Secondly, once the bike is started, does the red light go out when the RPM gets above say 1500? Also, a problem if that doesn't happen. For the first situation, if you have no red light initially, then it's possible that the bulb for that is burned out. The Airhead charging system is funny in its setup...there must be working bulb in the circuit for the charger to work.

The next easy step is to measure the voltages at the battery terminals with the bike running at say 3000 RPM. Do that and report back. It should be well north of 13v, even near 14v. Then we can go from there.

Thanks for your help, I guess that re light going on is a good thing. Just went out to start it up and we are good to go. Thanks for your help! Glane

 

[PGlaves]

Charge the battery.

Then with a volt meter attached to the battery posts read the voltage.

Key off, just sitting there = ?

While the starter is cranking = ?

While running at least 3,000 rpm = ?

Report back and we can opine a diagnosis.

 

[lkchris]

Recommend this: if you aren't going to ride your bike tomorrow, attach a trickle charger.

Batteries are sometimes more formally called "storage batteries" and these small batteries don't store much.

Recently sold my R80G/S which due to space limitations was relegated to back patio and consequently not ridden or even started for at least 3 years. Trickle charger attached the whole time. With some fresh gas, it started right up.

 

[glane]

R65 charging issues

Thanks for all the great advice. I have the bike on a trickle charger, fresh gas and a little dose of Seafoam. Starts right up. Still don't know what is going on with the stray wiring harness gizmo. Guess I should buy a manual. I know more about woodworking than Volts and Ohms. Greg.

 

[skibum69]

Welcome from Newfoundland, I have an '82 LS. Great little machine, tours better than you think it does.

 

[PGlaves]

Hi BMW guys and gals: Just picked up a 1981 R65LS. Back into motorcycling after a 20 year hiatus. Does anybody know whats going on with the lack of battery charging? I have a stray wiring harness plug where the battery tray is located. Do you think this was for a trickle charger? Thanks in advance for the assistance.

Can you post a picture of the "stray wiring harness"? It is probably an accessory connector for a battery charger, electric jacket liner, etc.

Does it look like this: