Lemmie get this straight...

Infernozx · #1 05-11-2004, 01:53 PM

I wire #1 to the battery positive (+) terminal.

I wire #2 to #1.

and..

I wire #3 to the ground side of a 12V switched idiot light.

Sounds like a plan?

jeeperjohn · #2 05-11-2004, 03:59 PM

That will work. But the voltage will be referenced to the back of the alternator (number 1) rather than a point farther down the wiring harness. You may want to look at this post. Alternator wiring

Infernozx · #3 05-11-2004, 04:17 PM

TeamRush saves the day again. [img]images/graemlins/grin.gif[/img]

and he hasn't even been here in a long time.

For reference.

So if I ran a voltmeter, I can dump the idiot light?

Or better yet dump the volt meter and run an idiot light?

And the #1 wire should run to something on the other side of the fuseblock that is switched (ign) 12V ? no?

Jim_Lou · #4 05-12-2004, 07:24 AM

</font><blockquote><font class="small">In reply to:</font><hr />
So if I ran a voltmeter, I can dump the idiot light?

[/ QUOTE ]

No. The idiot light in the drawing also serves the purpose of providing the resistance necessary to kill the ignition system when the switch is shut off. Without it current will flow backwards from the alternator to the switch, and from there to the ignition system, and the engine won't shut down.

The idiot light can be replaced with a resistor, a piece of resistance wire (the factory's solution on Jeeps without a light) or a diode.

And regarding where the 'B' connection is made, if you have a vehicle that uses a lot of electricity a significant part of the time, it's important that you connect as close to the battery as possible. That's because if there is a high current flow out of the alternator, there will be a drop in voltage between it and the battery. That will result in the battery not reaching its full charge.

If your vehicle doesn't normally use much electricity it's fine to connect 'B' directly to 'Batt'. I tested that on my Jeep and found no difference in voltage at the battery whether 'B' was connected directly to the battery or to the 'Batt' terminal of the alternator. But at the time the only electricity it was using was to power the ignition system. If you have lots of lights, a winch, or some other high-current device, where 'B' is connected can make a difference.