The big wire terminal on the back should go to the ammeter (or battery if
you're using a voltmeter instead of the ammeter). For the other two wires,
buy a plug from NAPA or whoever to fit the socket in the alternator
housing. It comes with a couple inches of wire. The furthest terminal from
the Batt terminal is the voltage sense terminal the closest one is the
exciter terminal.
The voltage sense wire for the regulator can go to the big terminal if
you're lazy but is better run to somewhere else if you want the voltage
regulator to compensate for line loss in the wiring harness; the battery
itself is a good bet, or the battery terminal on the starter.
The other wire is for voltage to stimulate the exciter diodes (diode trio)
that get the whole business charging from a dead stop. Without it the
alternator will not function until it turns about 6,000 RPM for the first
time and then everything will be normal. This wire usually comes from the
idiot light and grounds the light through the regulator. GM has used a 160
ohm resistor in parallel with the bulb incase it burns out. Since I don't
have an idiot light, I tried running a wire from the ignition switch
through a 160 Ohm resistor to the exicter terminal. This worked fine until
one time I tried to shut the engine off at full throttle to do a plug check
and it kept running. So, I replaced the resistor with a diode and
everything has been fine since. If you are running an MSD ignition you must
use the diode rather than the resistor or you will not be able to shut down
the engine even at idle.
Tom Allen
51 3800
At 11:17 AM 1/7/02 -0500, Randall J. Krebs wrote:
>I have a GM Alternator ('74 Impala 350). It has 3 wires coming off it (have
>been told this means an internal voltage regulator). Which wire goes
>where.
>
>Thanks
>
>Gibbon website is www.gibbonfiberglass.com I used their front cross member
>kit if anyone wants to email me for my comments. (from the question above
>it's obvious that it was simple to install and obviously isn't on the road
>yet)
>
>Gibbon also has fibreglass kits to convert a stepside into a Cameo
>
>Randall J. Krebs
>oletrucks is devoted to Chevy and GM trucks built between 1941 and 1959
Tom Allen
Seattle, WA
oletrucks is devoted to Chevy and GM trucks built between 1941 and 1959
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