just bought an amp guage , is there a hook up besides at the altenator, like the drawing shows ? if not where should I splice or hook up to?

Run a really big fat wire (at least as fat as the thick red wire on the alternator) from the alternator to the gauge, and from there to the starter?

--DD

What an amp gauge measures is the current flowing through it in either direction, that's why the scale read + or - from zero.

You can hook the gauge up as Dave said. This will show what the alternator is putting out, some of it powering stuff in the car and the rest charging the battery. Hooked up correctly the gauge will always read on the + side.

You could also join the four red wires at the + battery post together and hook the gauge between them and the + post. This will show you how much power the stuff in the car is using. The gauge will always read on the - side.

The gauge would be most useful if the four red wires at the battery and the alternator output were all hooked together and the gauge was installed between them and the + battery post. This would show when the alternators output exceeds the vehicles consumption and the battery is getting charged, the gauge reading on the + side. And it would show when power consumption exceeds the alternators output and is being supplemented by the battery by reading on the minus side of the gauge. This could be caused by low engine speed, a loose alternator belt, high power headlites, a killer stereo amp or a combination of these things. The result may be a chronically undercharged or dead battery.

However you install the meter, use heavy gauge wiring. A long run of small wire or poor connections will cause problems.