Voltage drop with ignition on?

[chattownxs]

Hey everyone, new to the forum. Just got finished chopping my 81 XS yesterday and took her for a ride to work last night. It's about 15 miles one way. Coming back this morning I was about a mile from home and just got off the freeway when the bike didn't want to idle. I thought it may have been running low on fuel so switched to reserve. It died so I kicked her back and barely got home. while running when I gave it gas it would cut out and die and it felt like the carbs. Noticed the headlight was dim so tested the battery and it was good, right at 12 volts but when I turn the key on it immediately dropped to 5 volts and kept falling. I just installed a Pamco kit when I chopped it too. It ran fine on the way to work and about 50 miles before work yesterday. Any ideas? Any help would be appreciated.

 

[willyguzzi53]

Sounds like bad battery or connection. Could be bad ground too. Should hold 10v or so with everything turned on that you have.

 

[Grinder]

You should check your charging system to make sure it's working. Plenty of info here on that. Should be 14.5V or so at about 2500-3000 rpm. The Pamco will work down to about 6V I believe.

 

[chattownxs]

I was thinking it would be a bad ground but I only have 3 grounds. The battery, headlight and ignition. The tail light grounds at the case. I just replaced the rotor about 500 miles ago. Hope that isn't it. I will look into it tomorrow and let you know what all I find.

 

[chattownxs]

I didn't have all that much time to check it out today. I did have some voltage drop at the ignition switch. The bike was charging at about 13.5 volts if revved. The magnetic field created by the rotor wasn't the strongest but still pulled my feeler gauge in with the cover off. I will have to do some more searching when I have more time. I think I have an inconsistent short somewhere that pops up every now and then. I have noticed on the freeway ever since I have had the bike that the head light will dim for a little while then get bright again. I just can't figure out what is causing it.

 

[XSLeo]

How about the ground for the regulator? Have you used your meter on a low ohm setting to check the grounds? A good ground will have near zero ohms.