[Feener52]

Hi Everyone,

I have a bit of head-scratcher regarding my bike; a 2002 Bonneville. About a week ago, I began noticing the bike struggling to start while hitting the ignition. It would click initially before turning over and starting. This problem was intermittent for a few days but then became worse and worse.

Finally a few days ago, I went out for a ride to my parents. I parked the bike for a few hours and when I tried to start it again, I just got a bunch of clicking. No firing of the engine or turn over. I then bump-started the bike and drove home. The bike operated fine the whole way back to the city.

When I parked the bike, I began smelling a "rotten egg" sulphur odour. I popped the seat and found that the battery was smoking and was too hot to touch. It was so hot that it popped one of the cell rubbers and was smoking out of it. I waited a few mins and removed the battery, left it overnight and checked its voltage in the morning. It was around 13v. I still didn't trust it so I went out and bought a new battery, charged it, and threw it in the bike.

When I turned the key, the indicator lights and low beam turned on as usual, however when I hit the ignition I had a split second of clicks before a complete loss of power. No lights anywhere, no ignition, nothing. I thought I had blown a fuse but when I checked, no fuses appeared to be blown.

I thought given the overcooked/blown battery that maybe my regulator-rectifier was toast, causing the battery to overcharge and "cook", but I didn't think that it would affect the bikes ability to start. As it stands now, I have absolutely no power at all. Any troubleshooting tips or suggestions of what the problem may be would be greatly appreciated.

Thanks,

- Zach

 

[johnpainter]

Your description does sound like a classic case of a cooked battery, but you need to do some testing to confirm. Another possibility is a short to ground in the wiring harness or battery cables, which would certainly explain a hot battery. It's also not impossible that the new battery is internally shorted. Before you do anything, a thorough visual inspection with a flashlight and patience is in order. Start at the battery and follow the cables to the harness, turning over the cables in your hands to look for bare wires or scorch marks. Look also for loose connections or stray wires. If you have any aftermarket items such as lights, alarm or GPS, check those carefully for the same.

If nothing is obvious it's time for electrical diagnosis. I'm linking several videos below. Some of the testing may be difficult if you cannot start the bike at all, though you may be able to bump-start the bike again to test the charging system. The battery you may need to disconnect and remove from the bike for testing on a load tester at an auto parts store if the bike simply won't start. The linked video assumes that you can use the starter as a test load, but that won't work if it won't start! It is possible that you've cooked your new battery either with a short to ground or with an overcharge. Be cautious and work in an open area outdoors. Battery gases can explode if they become concentrated.