New "CS" alternator on old 427

[Gene M.]

I have a wiring problem with using a new style GM alternator for 1997 and newer vehicles and adapting it to a old 427. Alternator is internal fan and set up to be 165 max amp output. I think it is refered to as a "CS" style alternator. My 97 Silverado has an alternator just like it except it's only 105 amp. The original application (as in my Silverado) uses only two wires total. The typical large gauge wire that goes to the starter solenoid via the battery and a small gauge that plugs into one of the 4 pins. This smaller wire is the one that gives me questions. What does it connect to? I assume the ignition switch via the generator lite bulb or should it go to some known resistor? I remember reading some artical that stated the small wire is only an "exciter" to start the alternator charging. Is this true? Does it need a oneway diode? Any help is appreciated I do not want to destroy this unit by wiring it wrong......
thank you

[Wayne W.]

Re: New "CS" alternator on old 427

You had better think about how to mount it first. The new alternators do not live long when mounted the old way on the exhaust manifolds. If you do not isolate it from the heat, it wont matter how you got it wired up.

[mike cobine]

Re: New "CS" alternator on old 427

I wouldn't give you 2 cents for one of these alternators. I've replaced about 8 or so of them on a couple of different vehicles, so it wasn't a vehicle problem. One I did on the way to Bloomington in 2005, near Rome, GA.
Tow vehicles are not supposed to be the unreliable one.

If you need that much power in an old car, I'd find someone who builds the old alternators to the higher output levels instead.

If it is in a newer vehicle, then use the serpentine belt brackets to hold it away from the heat. They can be found off most 1 ton Chevy and GMC 454 trucks.

The terminals are P, L, I, and S. Either L or I must be used to turn on the regulator. L must be connected through a resistor or an indicator lamp. I can be directly to the 12v battery positive. The P terminal can be used for a tach. The S is for external voltage control.