Re: Alternator help needed

[Matt Haas <mhaas@xxxxxxx>]

This is wrong. If you attach the field wire directly to 12 volts, the magic 
smoke escapes from the electronics. Once that happens, the alternator is dead.

The field wire needs to have some resistance in it to keep this from 
happening. In a car with a warning light, the light bulb takes care of the 
resistance. If you don't have a warning light (you need a voltage gauge in 
this case), you need a resistor in the circuit. If you don't hook that wire 
up to anything, the alternator will not charge.

The other wire is a voltage sense wire. That wire can be hooked to the 
battery charge terminal but a better place would be either to the battery 
post, the battery cable where it attaches to the solenoid, or (if your car 
has one), a power distribution block. If you leave this wire disconnected, 
the alternator will produce max amperage and will burn out in short order. 
If you're really lucky, this could also set your wiring harness on fire.

If you want a real one wire alternator, you need to get one that has 
self-exciting guts. I think the difference is just in the electronics but 
there are a lot of real one-wire Delco 10si style alternators on the 
market. PowerMaster (I have one of these) makes them that work both ways 
for more flexibility.

Matt

At 10:44 AM 5/19/2005 -0400, you wrote:
> An alternator has to have some battery voltage going to it to excite the 
> field before it will charge. A standard Delco alternator can be made into 
> a one-wire by simply attaching the field wire to the battery cable stud on 
> the back of the alternator. The other wire in the two prong connector is 
> for the alternator light on the dash.
>
> You're going to have to study the original Motorola wiring diagram and one 
> for the Motorcraft external regualtor. You may have to move some wires 
> around and/or leave some disconnected. Some of the wires aren't used when 
> you switch from a generator to an alternator.
<snip>

mhaas@xxxxxxx
Cincinnati, OH
http://www.mattsoldcars.com
1967 Rambler American wagon
1968 Rambler American sedan
===============================================================
According to a February survey of Internet holdouts released by
UCLA's Center for Communication Policy, people cite
not having a computer as the No. 1 reason they won't go online.