Grounding out?

I have a 1982 KZ440, was running fine then one day just dead (no power, no lights) not far from my place, pushed it home.  Charged the battery, reads 12.6 volts, brand new, half a season on the battery.  Dropped the battery in bike fired up tested voltage while the bike was on, reading 14.50-15.00 volts so charging is working.  I turned the bike off, went back upstairs to put the tools away grab my helmet.  Now head back downstairs turn they key no power, no lights.  Battery with the key off is 12.6 volts,  turn the key turns to 0 volts.  

Disconnect the positive and tested the ohms, i am getting very little ohms with the postive probe on the positive lead and holding the negative probe on the ground.  So probably grounding somewhere.  Checked all the connections, they look fine.  Was wondering if maybe a bad starter solenoid or ignition switch could cause this, and how to test?


any one have any ideas?  i am at a dead end

Try to disconnect all wiring harness connectors step by step.
If your Ohm reading goes to --- (endless) you know this the wiring harness you have to search for a hidden shortcut.
Some multimeter have a acoustic beep position that makes it more comfortable. 
Remove the battery first or you will destroy your multimeter!!!

If there was a short to ground on a non-fused circuit there would be a fire (ie: the positive battery cable). A short to ground on a fused circuit would blow a fuse. A bad ground breaking the main power circuit could cause your symptoms.

Get a charger, or jumper cables from your car battery, and see if it starts every time. If so, replace the battery.

I've seen more than one cheap bike battery go from fully charged to nothing, with the turn of the key, due to an internal open circuit.

So it was actually the battery that had gone bad. However, it was a brand new battery, maybe a few months old, which sucks.

VTEC wrote: ...I've seen more than one cheap bike battery go from fully charged to nothing, with the turn of the key, due to an internal open circuit.

Yup. That.

Years ago there was a spate of U.S. manufactured Yuasa motorcycle batteries that were notorious for that. Also marketed as Interstate and Sears DieHard. Symptom: measured open-circuit with a DMM, battery would show ~13.2 volts, but would drop to near zero volts with any kind of load. Wouldn't even power a headlight. We sent two batteries back to Yuasa USA in vermiculite packaging they provided so the could evaluate the failures. Never heard anything back from Yuasa.

Around year 2000 there was an article in the now-defunct Sportbike Magazine in which they did diagnostics of otherwise healthy batteries that had experienced the same sudden failure behavior. Without exception, they found an internal weld between cells had failed. We've looked for the article since with success.

We haven't bought a U.S sourced Yuasa battery since the 4th. or 5th sudden failure we experienced. All were less than 2 yrs. old. We've never seen a Japanese Yuasa fail like that, only the U.S. manufactured ones.

We've bought Taiwanese batteries from WalMart and a few Chinese batteries from Meijer for 15 rys. with a single sudden failure.

Out takeaway: just 'cause a battery reads ~13.2 v doesn't make it a good battery. A load test will tell the tale every time.


Good Ridin'
slmjim & Z1BEBE

Maybe I've been lucky, but I've never had the open circuit scenario with a Yuasa. Yuasa YB18L-A is the OEM battery for my KZ, and have yet to find another brand that fits correctly. They're either too tall, too narrow, terminals out of place, etc. even though the catalog says they fit my bike.