Alternater output varies greatly

[Ross/Kzoo]

This spring when I went to start the A she started right up----great. When I tried to honk the horn and turn on the lights and check the tail lights---nothing. I checked the voltage at the alternator and it read from 0 to 12 volts. Maybe these two issues are not related but I need help to trace down my problem. Thanks in advance Fordbarners.

[Tom Wesenberg]

What volt battery are you using? The post at the alternator should read battery voltage with the engine off, and should read alternator output with the engine running. Hopefully the output is a bit more than battery voltage.

If you are measuring eratic voltages with the engine off, I'd say you have a loose connection somewhere in the charging circuit. If you use a fuse I've heard a lot of them get loose connections. You could use a the clip lead that you carry in your tool kit to jump across the fuse. If that doesn't fix the problem use the clip lead to jump across the 2 wing nuts on the terminal box to eliminate the amp meter and it's connections.

[Brentwood Bob]

Do you have an auxilary ground strap?

[Ice man]

Watch the amp meter. If its gets hot to touch it could burn up, literally. I don't trust them and got a volt meter from Snyders, it fits right in the dash panel with no cutting. Iceman

[Tom Wesenberg]

Sponsored Links (Register now to hide all advertisements)

Originally Posted by Ice man

Watch the amp meter. If its gets hot to touch it could burn up, literally. I don't trust them and got a volt meter from Snyders, it fits right in the dash panel with no cutting. Iceman

The amp meter only gets hot if it has a poor connection or a short to ground. Both are easily preventable with proper maintenance and rebuilding. When some guys rebuild the amp meter they solder the studs to the bus bar for a foolproof connection. If the connections are clean and tight that should do fine.