Well, I did a single wire alternator on my 72 GS and found it was killing my battery when it sat for long periods of time (4 weeks or more). I thought there may be a problem with the alternator or the car it self and I was told a alternator shop this is normal and to disconnect the battery if the car sits for long peroids of time. I was told even the newer internal voltage regulator GM have a continue draw with key off. The original GM external voltage regulator has no draw with the key off. I think I will be going back to the old system on my car, AL.
Al, I just noticed your thread on the alternator. I put an 1977 65 amp GM SI (internal regulator) alternator on my 55 Chevy some years back and never had any trouble. The wires where: The one 10 gauge hot to the batt terminal. I will have to double check this, but I think it was # 1 pin to the idiot light and the #2 pin jumpered to the batt wire. WORKED GREAT! Never had any problems with battery discharge. I will take a look this weekend and see if the two are correct for hook up location. If they need to be swapped, I will drop a message on the thread.:3gears: Doug
the single wire alternator does not draw any juice with the ignition off. at least i never saw any draw via my digital meter. sounds like u may have a bad wire/connection/ground at the alternator. a battery loses about 10% of its cranking power each month if left unused and even more when temperatures fall. i know for a fact that the late model corvettes do draw from the battery when the ignition is off. a lot of its electronics need a power to retain their settings, especially the computer boards. my friend has a beautiful 2003 vette and he has to start it ever 10 days to preserve the settings and maintain a sufficient charge in the battery.
Gerry, as far as my GS, the alternator I installed does have a constent draw and is normal. The applacation was for a Bobcat and they have a power disconnect so power drain is not a issue. As far as you post on power draw, I disagree, a self exciting alternator needs a continued power source to activate the charging system after the alternator picks up speed, AL.
Doug, I may look in to the newer GM internal voltage regulator. My alternator rebuilder told me the GM internal style do draw continued battery voltage but no where near what the single wire style draw, AL.
I thought the internal regulators were solid-state, and all solid state devices were subject to leakage current (albeit pretty small amounts of current hopefully). Maybe I'm wrong. -Bob C.
I have as number of vehicles that all have "single wire" alternator setups, both the older type internal regulator and the small diameter ones, and none of them drain the battery when they are parked for any length of time. I have had rotten results with all the Optima batteries I have ever used, they are just plain junk, from my experiences. I only had two other wet cell batteries go dead, two brand new CarQuest 72 month "Extreme Service". Its warrantee replacement was the same make and style, and it too, went dead, both in less than two weeks. They were both replaced with a very inexpensive battery from Kragen's, over a year ago, and it still works fine. Regards, Milton
you will get constant draw on a 1 wire,but not enough to kill a battery in 4 months.however,there are multiple 1 wire regs,not created equall.the bobcat uses circuitry designed for power assisted turn-on,due to the low rpm nature of the machine,and it has a bridge to the "sense"terminal,so it CAN draw the battery down while sitting since it has an AC tap to the rectifier.if you want to do it correctly,get a 1 wire regulator for marine use.and an alternator DOES store residual magnetism in the pole pieces of the rotor for the initial turn-on,in an automotive application,this is done by rpm's.however,that can be lost if not "energized" for long periods of time.you know the shadetree mechanic trick of"putting a scredriver to the rear bearing & feeling it pull"to see if its charging,that is the magnetism stored in the pole pieces,it's allways there,but stronger during charging.
Hey guys, I found a website for a company called MAD Enterprises (www.madelectrical.com) and they have a very comprehensive comparison of the 3-wire vs. 1-wire alternators. http://www.madelectrical.com/electricaltech/onewire-threewire.shtml They basically show that the 3-wire alternator is MUCH better than the 1-wire alt and even explain how to properly wire one up to a classic GM muscle car (they use Chevy as an example but I won't hold it against them). I highly recommend reading the entire article... it definitely convinced me to ditch my 100 amp 1-wire alt and go with a 94 amp 3-wire alt instead!
Are they basically saying to run a wire from the voltage sensing terminal on the alt to the factory junction in the wiring harness instead of using a jumper wire between the voltage sensing terminal and the bat terminal on the alt? o No: Brad.
I have a 64 Skylark, and would like to change to the single wire Alternator. Do you a diagram for this?
