Alternator Replacement
Thread Starter
Drifting
Joined: Jan 2002
Posts: 1,645
Likes: 11
From: Schaumburg IL
Alternator Replacement
I need to change out the 10Si alternator on my 73 BB Coupe as it is charging upwards to 15 volts -- don't want to cook the battery. Summit Racing has 10si units in 100 and 140 amp, good replacement for the stock 63 amp.
Question -- since these are "one wire" hookup can I use the stock wiring or best to run a 6 or 4 grade wire directly to the BAT post on the Starter for safety with increased amp output?
Question -- since these are "one wire" hookup can I use the stock wiring or best to run a 6 or 4 grade wire directly to the BAT post on the Starter for safety with increased amp output?
Drifting
Joined: Mar 2011
Posts: 1,347
Likes: 121
From: Kernersville NC
First you will get multiple responses and numerous reasons why a 1 wire alternator is a bad idea. I've been running them for years with no problems,. To each his own.
The alternator amp rating is only what it is capable of providing the system if asked to do so. It does not supply 63, 100, or 140 amps unless your system asks for it. If you have a basically stock car and electrical system your 63 amp alternator may be supplying 30-40 amps with all lights on, heater or a/c blowing, and the radio volume turned up. So in that case it is working at about 50-60% of it's capacity. If you put a 100 amp alternator on your car (and add no additional electrical load) it will be working at 30-40% of its capacity. That will require no new rewiring. If you start adding an amp, electric fuel pump, electric fans, then you would want to upgrade your wiring.
The alternator amp rating is only what it is capable of providing the system if asked to do so. It does not supply 63, 100, or 140 amps unless your system asks for it. If you have a basically stock car and electrical system your 63 amp alternator may be supplying 30-40 amps with all lights on, heater or a/c blowing, and the radio volume turned up. So in that case it is working at about 50-60% of it's capacity. If you put a 100 amp alternator on your car (and add no additional electrical load) it will be working at 30-40% of its capacity. That will require no new rewiring. If you start adding an amp, electric fuel pump, electric fans, then you would want to upgrade your wiring.
Burning Brakes
Joined: Jul 2016
Posts: 767
Likes: 74
From: Blaine MN
You may want to check your battery cable connections, sometimes a poor connection causes the Regulator to full field (not common but can happen).
I'm guessing in 73 it is an internal Volt. Regulator, you can rebuild the Alt. and put in new Regulator as an alternative (if it's high miles Vehic. it may not be worth doing tho).
I'm guessing in 73 it is an internal Volt. Regulator, you can rebuild the Alt. and put in new Regulator as an alternative (if it's high miles Vehic. it may not be worth doing tho).
Race Director
Joined: Apr 2007
Posts: 11,152
Likes: 890
From: South Western Ontario
There is always a chance of a fire any time you put in components capable of more current than the wire can handle. Sure, lots of people do it without issues, but the chance is still there.
If your car is stock, then a stock type replacement will work just fine and not require any changes to the car. As an example, $47 with the core charge.
https://www.summitracing.com/int/parts/ado-334-2114
If your car is stock, then a stock type replacement will work just fine and not require any changes to the car. As an example, $47 with the core charge.
https://www.summitracing.com/int/parts/ado-334-2114
Le Mans Master
Joined: Oct 2006
Posts: 7,123
Likes: 433
From: Gladstone MO
C3 of Year Finalist (appearance mods) 2019
Going to a "Big Name" alternator gets you nothing but bragging rights. A rebuilt from your local parts store will take care of your battery just fine. You could even go real thrifty and just replace the brush holder and regulator if everything else tests good.
