Voltage drop at battery when neg cable is installed

[griz69]

I have a weird problem..... I get a voltage drop at battery when neg cable is installed. My battery is brand new, the battery has 12v when just the pos side is hooked up but as soon as I install the neg cable the voltage drops to 8v which obviously isn't enough to start the bike. I checked the ground wire to the engine and it is fine, I even ran a new one to be certain but same deal.... here's the thing, I put a booster pack on the battery and the bike starts?? I can tell right away that I get my 12v because the neutral light gets brighter.... I need help with this one!!! Thanks

 

[griz69]

I have a weird problem..... I get a voltage drop at battery when neg cable is installed. My battery is brand new, the battery has 12v when just the pos side is hooked up but as soon as I install the neg cable the voltage drops to 8v which obviously isn't enough to start the bike. I checked the ground wire to the engine and it is fine, I even ran a new one to be certain but same deal.... here's the thing, I put a booster pack on the battery and the bike starts?? I can tell right away that I get my 12v because the neutral light gets brighter.... I need help with this one!!! Thanks

sorry its a 99 600 grizzly

 

[maim]

how does the battery test out with a tester? might have a bad/weak cell.

 

[the Wolfman]

Sounds like your battery may have a weak cell. A good battery should show 12.6 to 12.8 vdc after a clean charge. There are other reasons for a heavy voltage drop, but without more info it's hard to tell you anything substantial.

 

[griz69]

Thanks guys it was the battery, the battery was fairly new that's why I never deemed it