Re: wiring questions

Posted by Rusty O\'Toole On 2008/9/4 18:26:19

A word of warning if I may.

The diagram appears to show the alternator "Field" terminal connected to battery power. This will work, but is not a good idea.

If a standard alternator is connected this way the field will be energized all the time. The wasted current will slowly discharge the battery, killing it in a week or 2.

The correct way is to connect the field to keyed power. In other words the "On" terminal of the key switch.

It is possible to get around this by using a "one wire" alternator. This is an alternator with a special voltage regulator made for diesel tractors, dump trucks etc. It is called a "self exciting" regulator.

There are a couple of drawbacks to this alternator. One is, it is slightly more expensive. Another is, that sometimes it does not kick in until you rev the engine to 1800 or 2000 revs. As long as you are aware of this and keep an eye on the amp gauge you can stamp on the gas pedal and get it going. O ya, you have to run an amp gauge or volt meter because it has no gen light wire.

On the whole it is best to just wire the field to keyed power and use a car alternator.