My alternator is not charging. I think I have it hooked up wrong

[svsonora]

Please see photos attached.

The two wires connected to EXC in the photos are the only ones that connect to the engine. One goes to starter, other goes to ignition switch.

Also, what are the bottom two covered posts? Are these whats called 'AC Tap' ?

[smac999]

you can't connect those 2 wires together. your "key" would always be on.

the starter post wire (from the battery) goes to "B" for battery.

ac tap would run a tach

[rgleason]

How is this grounded?
1. Dedicated wire.
2. Through the engine. Looks like a separate mountingg.
3. Alternators sometimes are ground isolated and need a dedicated ground wire others are not.

[Stu Jackson]

Alternator Handbook is helpful, too big to upload, use Google.


The reality is that you need to learn what wires are what and photos of wiring without a wiring diagram are harder to help you out with.


Good luck. We've all BTDT and figured it out. Then we drew the wiring diagrams. Sometime maybe ONLY then...

[donradcliffe]

Not all alternators use the same connections, and there is no universal code for the terminals. You are best off getting the wiring diagram for your particular alternator.

That being said, I would move the wire from the starter (which also goes to the battery) from the EXC terminal to the B terminal. The EXC terminal should be connected to the ignition wire, so the alternator will only be excited when the ignition is on. The S terminal is probably for external voltage sensing, and is jumpered to the B terminal in this installation (you might get better performance if you ran a separate wire from S to the positive battery terminal, but you have to fuse it and you can really screw things up if you switch to a different battery. The E terminal on this alternator appears to be for earth, or ground, but this installation is probably grounded through the alternator case and mount.