Mike, Maybe check out the linked info page in this very old on-topic discussion. I just scanned through the linked info page and think it may still be valid and helpful information. You can also search through previous Stovebolt conversations on the subject, including about the fan belt width issue by using the Stovebolt Search link. Hope this may be a little help.
Last edited by Gdads51; 08/26/20241:50 PM. Reason: add direct link to source document
~ Dan 1951 Chevy 3 window 3100 Follow this story in the DITY Gallery "My Grandpa Carl's Truck and How it Became Mine" 1966 Chevelle (Wife's Hot Rod) | 2013 Chevy Silverado (Current daily driver) US Army MSG Retired (1977-1998) | Com Fac Maint Lead Tech Retired (1998-2021)
I will be using a wide fan belt, so the pulley may be an issue
These guys have wide belt pulleys for alternators as well as mounting brackets for Chevy .
'57 GMC 102, Original 347 V8, HydraMatic, 3.08 rear gear, added A/C, disk front brakes, HEI, AFB carb, '98 Honda Black Currant paint. T-boned and totaled 10/12 '52 GMC 152 Stake Bed, Original 228, SM420, added A/C, HEI, disk front brakes, '67 Chev 3.55 rear gear. Gets used as a real truck.
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
You don't need a "one" wire. A three wire only has two wires to route. One wire more than one wire. The so called three wires are: the battery cable on the alternator power stud, the sense jumper (alternator blade 2) and the exciter wire to Ignition switch. (alternator blade 1)
Here is a list of "advantages" of "one wire" from a supplier. See anything that is not snake oil?
Simple installation.... OK good, both use same bracket and bolts, wiring no factor Single wire installation....covered that Built-in voltage regulator...... both do Eliminates excess wiring.....excess? Low RPM turn on and charge........wrong Fits factory applications.....both do Low and high current applications......both do Multiple finishes available..........both do
ONE WIRE NORMALLY MORE EXPENSIVE.
Last edited by bartamos; 08/29/202412:12 AM. Reason: clarification
I would second Bartamos's suggestion of a 3 wire alternator because having the sense line at the battery eliminates the effect of voltage drop in the alternator harness.
The one wire is convenient, but not really "good". To repeat a common refrain "if one-wire setups are better and cheaper to install, why did none of the manufactures use them from the factory?"
... and if you decide on a 3 wire (I did) run the sense wire back to a good place in the harness (I used the battery cable where it connects to the stomp switch) instead of just connecting the sense wire to the alternator's output, which effectively turns it back into a one wire alternator.
'57 GMC 102, Original 347 V8, HydraMatic, 3.08 rear gear, added A/C, disk front brakes, HEI, AFB carb, '98 Honda Black Currant paint. T-boned and totaled 10/12 '52 GMC 152 Stake Bed, Original 228, SM420, added A/C, HEI, disk front brakes, '67 Chev 3.55 rear gear. Gets used as a real truck.
This brings up a VERY important 3 wire install point. The exciter wire. The "one more wire". This wire allows a tell tale dash light if you want that. If you don't, the exciter wire (alternator blade 1) needs to go to a "switched power source". All the instructions keep saying that. "Switched power"....It is true....but..... The ignition switch is the place of choice. Then sometimes folks have "run-on". The motor won't shut off. So everyone panics and says add a bulb, add a diode, a flux capacitor. Well hold on a minute. The feedback, if there is any, is power going backwards up the exciter wire to the coil and keeps the points firing. The term "switched power" means power that is switched on and off. So when the installer attaches the exciter wire to ignition "ON" terminal, they think they are getting switched power. Yes and NO. The ignition "ON" terminal is indeed off when switch is off. But the exciter wire is effectively spliced to the coil wire via using the same terminal for both. The backwards alternator power just bypasses the switch and continues to coil. So when hooking up the exciter wire, hook it to the accessory terminal, which is a switched power. Be sure to verify that it is on when ignition switch is on and off when switch is off. Be sure that there is no other live power wire on ACC terminal.
Using a bulb, just for run-on, supposedly eats the amps/volts so that there is not enough to fire points. Using a diode blocks the backward flow on exciter wire. The ACC terminal method prevents coil from getting voltage when ignition is off. That's the "switched power" that no one explains. I have discussed this before, it's in Stovebolt search.
Remember that the "one wire" is called a self exciting alternator but takes a rev or two to start charging. Go figure. The self is YOU.. The three wire is auto exciting.
Last edited by Rusty Rod; 08/27/20241:14 AM. Reason: clarification. unnecessary statements.
Instead of a light bulb (and maybe a diode) for the "exciter wire" I used a 12v LED in my truck. The LE (Light Emitting) part of the LED comes on bright when the key is on and the alternator is not charging. The D (Diode) part of the LED prevents run-on.
2 birds, 1 stone.
'57 GMC 102, Original 347 V8, HydraMatic, 3.08 rear gear, added A/C, disk front brakes, HEI, AFB carb, '98 Honda Black Currant paint. T-boned and totaled 10/12 '52 GMC 152 Stake Bed, Original 228, SM420, added A/C, HEI, disk front brakes, '67 Chev 3.55 rear gear. Gets used as a real truck.
I use a one wire on all mine. Voltmeter hits 14 ,its charging. Wrong or right I set my idle to the voltmeter reading just gets to 14.4. Works. ACDelco Silver 334-2110 Alternator, Remanufactured for the 235. The other 2 are CVF
Did the corner auto parts store run out of 10SI alternators? They only had a 30-something year run on every vehicle General Motors produced! Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
The 10Si series alternator was the first internal Regulator Alternator widely used by GM. The Si stands for Systems Integrated" which means the alternator has the voltage regulator built inside the alternator. As opposed to the earlier 10DN series alternator which was an externally regulated alternator.
OK, I got a 12 Volt one from Amazon and switched pulleys from the 6V one I had. Will install when some paint drys. I will fire this engine up on the stand in the next couple weeks. Thanks all for the help.
Paint can be an insulator. Be sure the mounting bosses where the alternator bolts to the bracket that mounts it to the engine is bare metal. Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
Mike, Would you share the part number info from your alternator you ordered? Might make it easier for other Bolters to follow your route.
~ Dan 1951 Chevy 3 window 3100 Follow this story in the DITY Gallery "My Grandpa Carl's Truck and How it Became Mine" 1966 Chevelle (Wife's Hot Rod) | 2013 Chevy Silverado (Current daily driver) US Army MSG Retired (1977-1998) | Com Fac Maint Lead Tech Retired (1998-2021)
I recently swapped out the original generator for an alternator on my "58. I used an early 10DN type and external regulator ('68 C10). I decided on this setup as I would only need to run one 10ga wire to the terminal on the starter. Using the 12 volt regulator for the alternator meant I didn't need to change any wring to the ignition switch or Amp meter. I did add a separate ground from the alternator to the chassis.
Last edited by TUTS 59; 08/28/20241:56 PM. Reason: Add Images
~ Craig 1958 Viking 4400 "The Book of Thor" Read the story in the DITY 1960 Chevrolet C10 "A Family Heirloom" Follow the story in the DITY Gallery '59 Apache 31, 327 V8 (0.030 over), Muncie M20 4 Speed, GM 10 Bolt Rear... long term project (30 years and counting)
Come Bleed or Blister, something has got to give!!! | Living life in the SLOW lane
Delco America, of course. is no longer casting 10si cases. So the rebuilders collect cores and some rebuild your old one. The "new" aftermarket cases/look-a-likes are cast in China. Not always a given, when you buy a rebuilt one, whether it's a rebuilt Delco or a rebuilt China clone. Check Markings, PN. logos and vendor statements.
The Amazon alternator I linked says it's an ACDelco, country of origiin....USA. I would never paint or chrome one.