Mysterious electrical issue

[Port]

1981 XS650-sh

So, the first time i took my bike out it just cut off with no sputtering or anything. It had been running fine for 15 min and then it was like someone hit the kill switch. When i got it back home it had no sparks. The wiring harness was the stock one with some bits and pieces replaced, it was a mess. I ordered a new harness from Mike's and got it all hooked up, all the lights, indicators, and horn were working but, i needed to fix the float heights before I could try starting it up. The next weekend i got the carbs put back on the bike and... nothing.

Nothing happens when i turn the key, no lights no nothin

DMM set to voltmeter reads 12.2v
DMM set to batter tester reads 10.3v

Why is my DMM giving me 2 different voltage readings? is it just a bad piece of equipment?

Would a battery voltage of 10.3v be too low to make even the blinkers work?

How might I use my DMM to find the problem connection if there is one?

What are the likely culprits of this problem if not the battery?

LI or AGM battery if i need a replacement?


I suspect that there might still be issues with the electrical system but i wont know untill i get this issue fixed.

 

[retiredgentleman]

Sounds like your battery is not fully charged. What type of battery do you have now? How old is it? If your battery has set for a long period , then you must now charge it until it has a full charge.

 

[Port]

AGM, not sure how old. Those readings were after a night of charging with the appropriate charger, i just checked it again and it read 11.89v. what would be considered a long period? I stopped charging when the indicator light said it was done

 

[rbjenterprises]

I just ran thru a similar situation. My bike has points, PMA, FLA battery. The electric starter would not work but would kick start OK. I have a voltmeter on board. At low rpm 's the PMA would not put out enough to keep it running consistently, add a headlight and it was a crap shoot at a stoplight. I figured out it was a dead cell. The most charge it could hold was 10.8 volts which is dead in a 12 volt world.

I just got a new AGM battery and all issues went away, electric start works, does not stop at lights due to low voltage.