I suspect I need to get a diode in my alternator circuit somewhere also, since I can turn off the master power switch, and if the rpm's are high enough, the engine continues to run. Not a problem if I simply turn off the ignition first. Where does the diode go to correct this? Thanks, Dan
The alternator pictured above is a 3 wire Delco 10SI. One of the most popular for generator conversions out there. Delco's 3 wire for the lower amp ranges. Also it's very often converted to one wire operation and even used for old farm tractor conversions.
I havent used a diode in the last 2 cars that I have had and I do not remember my uncke using it in any of his cars and my battery never goes dead unless the jumper wire is connected to the incorrect spade connector. Asher JC whitney sells reducers. Or I usually see them at swap meets pretty cheap
For an internal regulated GM alternator, you get a clip for pins 1 and 2. This clip usually comes prewired with a red #10 wire on Pin #2 that you jumper to the output pin on the back of the alternator. The only other wire that goes on the output jack is the #10 wire to the starter battery connection, or the starter solenoid. This wire is usually fused with a #14 fusable link, or a 50 Amp fuse (painless has the fuses). This output wire is the wire that charges your battery. The other wire on the plug (Pin #1) is called the Exciter wire. It goes to the Ignition switch (powered when the ignition is powered, but not in the ACC position). It is usually a #16 or #18 white wire (in new plugs). You can run this wire through a 12 volt idiot light. One side of the light goes to the ignition switch, the other side to the alternator. The light comes on when you turn the key to ignition, and it goes out when you goose the throttle during startup. The alternator must spin past 1000 RPM to get it running initially. If you don't like idiot lights, then you can put a Radio Shack 276-1661 50 amp diode in this wire (you can also run the diode and the idiot light). Caution, the white stripe on the diode towards the alternator. Put a couple layers of heat shrink tubing around it after install. So in review: Fold the wire on the #2 alternator pin to the output jack, and run the #1 wire to the ignition switch through a diode, or through an idiot light, or both. Stand back and marvel.
Well just to add to the fun I'll tell you what I do. No diode's, no dead batteries-EVER- and no big revs to get the charging started. I hook the charge post wire back to the battery terminal on the solenoid. I hook the red wire from the plug back to the charge post of the alt. This is the voltage sensing wire so you can run it to wherever you want the alternator to read voltage from. If I was running a lot of electricals I would run this wire back to the fuse box or ignition switch. THEN...I run the white wire from the plug to the "I" terminal on the solenoid. The alternator only needs to be energized momentarily to begin charging and just energizing while cranking has always been enough for me. The "I" terminal is that "useless" small terminal on the starter solenoid. SBC (and other GM) guys is it the one closest to the oil pan. Ford guys it is the small one you are not using to energize the solenoid (start the car). Chrysler guys...Well I just have no clue for you. If anybody wants to argue I'll let you come visit a couple times. I have this setup on my old Ford tractor. You can mow on Friday afternoon, park the tractor and keep the keys with you for a week. Go out the follwing Friday and mow again without jump starting the tractor...Seems like a good test for me!...I p*** this one weekly. My alternator is a regular 3 wire GM. Part number 7127M-12 from Advance Auto parts. 63 amps, I think.
I use that terminal to byp*** the ballast resistor when starting. Useless on an HEI or Electronic distributor though...
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