Modern Buddy

I've got a Buddy 50 (2008) giving me trouble.

Short version: My scooter is not drawing battery power. Everything else works. So, only electric start, blinking lights, and the horn are affected. The battery and CDI are definitely good (both replaced). Any ideas what it could be, or what I should check to narrow down the problem?

Long version: My scooter started acting up during the winter, with the electric start being particularly flaky. Battery-related functions began failing with some frequency, so I assumed freezing temperatures affected the battery (I ride year-round). I replaced the battery, things worked fine for a day, then back to failing. The problem became more and more common until the scooter stopped drawing battery power altogether, so I figured I'd wait till the winter was over and try replacing the battery again. Come spring, I replaced the battery and fuse, but nothing changed. A month went by and it started working again for 48 hours. Then it went back to failing. I replaced the CDI... no effect. I have a multimeter, I've taken it apart a couple of times... any idea what I can test to find the source of the problem? I would just give up completely but the fact that it would come back to life for 48 hours is such a tease for me to keep tinkering.

I'm wondering if your bike just isn't charging the battery. Grab a multimeter and check the voltage at the battery terminals with the bike running, and the battery disconnected.

If you know for a fact that the battery is good (minimum 12.5 volts under a light load) then I'd start checking the battery cables and connections, especially at the battery terminals. Sometimes the connections at the terminals may look OK but corrosion on either the cables or the battery terminals may cause a high resistance or intermittent connection. Clean both with sandpaper then try again. Checking the voltage at the battery with just a multimeter and no load will not give an accurate indication of either battery life or electrical connection to the cables.

There's also the possibility that your charging system is not charging the battery since you said replacing the battery allowed the starter to work for a while. Connect your multimeter to the battery while the engine is running and see if the voltage there goes up with engine RPMs. You should see anything from 13 to 14 volts when reving the engine (with the scooter on it's center stand, please).

Thanks for the advice. After closer inspection, I could see the connection for the negative battery terminal is corroded. I took to it with a toothbrush and baking soda, applied some petroleum jelly, and the battery-powered functions started working again. It's a few days later now, and it's back to being inconsistent (like in the months prior to it seemingly dying). Any ideas for a simple way to fix this, or is trying to get more rust of this thing my best bet? It looks like this isn't a part I can easily switch out...I would have to buy the wiring harness (correct me if I'm wrong here).

Get a brass or steel cleaning brush from your favorite auto parts store, and scour that terminal and the connecting wire until they are shiny and new looking. Do both the positive and the negative. Also, check your inline fuse, and clean those terminals as well.

Stanza wrote:Get a brass or steel cleaning brush from your favorite auto parts store, and scour that terminal and the connecting wire until they are shiny and new looking. Do both the positive and the negative. Also, check your inline fuse, and clean those terminals as well.

Also trace the heavy black wire off the battery negative (-) terminal to the other end where it bolts to the frame. Remove that and do the same scouring operation there so you have shiny metal connections. This is your "ground" connection and, if it's not right, it can cause weird problems including problems that mimic other problems. Don't miss this step.