Charging issues

[chase482]

Hey guys!

I need some help. I have a 1987 Chevy c10 with 305 motor. Noticed my alternator wasn't charging and decided to replace it. After replacing my multimeter only reads battery voltage at the alternator or battery with the truck running. I inspected the wiring from the alternator to the battery down to the starter. I didn't see a fusible link. Truck starts fine just only reads 12-11.50v. The exciter wire comes out of the 2 pin connector and connects on the alternator positive post and the other wire goes through the harness into the fire wall. I've checked for continuity from the firewall to that connector all checked ok. The wire that goes into the firewall to the gauge I assume has 9v with key on engine off and 12v with engine running.any help is appreciated!

 

[Wes Harden]

Is the battery also 9v, measured at the battery with ground disconnected ? If it is the alt is working, and working hard, out putting 3v+ over battery voltage.
Do you have a plug in battery charger ? I'd charge the battery for a couple hours, then test again.

If you have battery voltage at the red wire to stud on alt the fuse link is probably ok. Though it could be only a few strands connected and any serious load may over whelm.

 

[chase482]

Is the battery also 9v, measured at the battery with ground disconnected ? If it is the alt is working, and working hard, out putting 3v+ over battery voltage.
Do you have a plug in battery charger ? I'd charge the battery for a couple hours, then test again.

If you have battery voltage at the red wire to stud on alt the fuse link is probably ok. Though it could be only a few strands connected and any serious load may over whelm.

Thank you for the help after further inspection I found the wire that runs into the dash has continuity with chassis ground. Everything I'm seeing that wire is power only. Possible rubbed or shorted wire? Thank you

 

[imiceman44]

Thank you for the help after further inspection I found the wire that runs into the dash has continuity with chassis ground. Everything I'm seeing that wire is power only. Possible rubbed or shorted wire? Thank you

Most likely.
Unless someone was in there before and connected it to ground.

 

[Blue85]

What do you mean by continuity? A light bulb is somewhat low resistance until it heats up.