Hagen Brothers farms,Goodrich ND | L8Bloomer - 4/13/2009 19:05
Jon, I agree with you on most points, but if you moved the "sense" terminal out to a buss bar or other 12 volt point away from the alternator wouldn't that use more of a real world voltage for regulation? Also on many systems like this I think the coil is fed full 12 volts ( bypasses the resister ) for starting.
Although the light is a standard way to excite the alternator, it can fool you if the light burns out. No excitation no charge! Found out the hard way on a Jeep many years ago.
Dave
Yes on the sense wire. Most factory GM wiring harness have the sense wire connected at least 3-4 ft from the alternator to compensate for some voltage drop in the alternator output wire.
You rarely see more than 1/2 volt drop through the system unless electrical loads are very heavy, most Ag applications do fine with the voltage sense right at the alternator, as long as the alternator output wire is 10-12 GA and in good condition.
In the case of my 64 model 4020 gas engine , I ran the sense wire all the way back to the starter to sense voltage as close to the battery as possible to get the full 14.6 volt output to charge the battery as high as possible. That model has a weak starter and needs all possible ZAP from the battery.
Not sure if I really improved it any, but that seemed like a good idea on the day I did it.
As to the resistor in the #1 excite wire, there are several ways to get er done, using a diode, an indicator light or a fixed resistor.
I still prefer the indicator light for these reasons,
1 The indicator light gives an instant visual indication every time you turn on the ignition, that the resistor(bulb) and all other exciter wiring is working .
2 A replacement bulb is available at most auto, farm and hardware stores for penny's
3 It serves as a visual charge/ no charge indicator.
Sounds like you missed the burned out indicator light for the same reason I catch myself doing. That is I instantly turn the ignition switch from off to crank without allowing a moment to check the warning lights.
I try to train myself, but find myself back to the old instant switch habit time after time. :-)
|
Wiring a GM 3 wire alternator
