Alternator wiring

[chpr1972]

I have a one wire alternator. It is wired directly to the starter and a hot wire to the car comes from there. In my limited experience with wiring I can see no reason that I can not wire my alternator directly to the battery as long as I have a fusible link in between.

thoughts??

[astroracer]

To start you on the road to knowledge I will ask you to go to this site and do some reading.
http://madelectrical.com/electricaltech/onewire-threewire.shtml
I think you will begin to understand why doing that would not be a good thing and also why a 1 wire alternator is not the best way to go for a car with a lot of accessories.
Mark

[TheJDMan]

I agree with Mark, I started with a 145amp one wire 12SI alternator and the performance was mediocre at best. Converted that same alternator to a sensing alternator by changing the internal voltage regulator. The charging performance is MUCH better. The ONLY advantage of a one wire alternator is the ease of installation. Mad Electrical is a great resource for all things automotive electrical. Also read his section on adding relays to the headlights.

[chpr1972]

Yes I have read about one wire alternators but right now I just want to get the car back on the road. The wire from the alternator goes to the starter and I would like to wire it directly to the battery instead, like I believe the factory does on some cars.

[andrewb70]

Yes I have read about one wire alternators but right now I just want to get the car back on the road. The wire from the alternator goes to the starter and I would like to wire it directly to the battery instead, like I believe the factory does on some cars.

I see no issue with doing that, but the sensing style systems are better, as others have stated.

Andrew

[astroracer]

I have to say just leave it where it is. With it hooked to the starter it will get a little bit of input for system needs from the power wire going to the fuse box. Hooking it directly to the battery will eliminate any of that sensing ability.
Mark

[MonzaRacer]

First of all leave the power wire going down to the starter.
See most GM have their main feed wire for powering fuse box there and run power wire to same point.
Redesigning an older car generally upsets a lot of things.
Also many of these cars had dash gauges and such that are designed to operate this way.
Now, one wire, IE alternators that have no trigger wires to the regulator tend to fail to charge if the idle speed is low. Many of these wont even charge till they hit 2500-3000 rpm.
See most of them use a resistor "strapped" across the field and stator terminals.
See on SI alternators the field is the key on wire, the stator is what FEEDS the stator windings/
The regulator controls the field current, maintains the stator current.
Vary the field strength. vary the amperage output.
The alternator never turns fully off or on in one wire setup.
The stator wire from regulator can pull straight from battery feed stud but the fiels wire needs to be on a fused, key on line, one not connected to ignition circuit or you get a back feed and car wont shut off and you will need a 400PIV diode in line.
And as for where the charge wire is an alternator IS to maintain and fill back up the battery after start, not a dead battery. And its made to run car while running.

[Mr Nick]

I used to be a fan of MAD, but then I found this site/supplier, and I've learned much more from Tony at CE Auto Electric then I did from MAD. Just my preference.

His books are a cheap investment.

http://www.ceautoelectricsupply.com/wiringbooks.html

[astroracer]

Yes, Tony is at the top of the list also. I have all of his books and have even talked to him personally about the wiring project I have with my van. That said the MAD site is a perfect intro for anyone who wants to dig into the whys and why nots of most automotive electrical systems. Easy to read and understand and Mark gets into the bread and butter real quick. There is nothing wrong with utilizing the knowledge of both men. I wouldn't play one off against the other in any way.
Mark

[TonyV]

i gotta second that about Tony......came across CEAUTOELECTRICSUPPLY by accident desperately needing a specific wire and color on a saturday and just by chance we was 5 miles away.....called him and let me come by and to say the least i walked away with a lot more "stuff" and a bit smarter on wiring. He was very helpful and willing to spend the time


I used to be a fan of MAD, but then I found this site/supplier, and I've learned much more from Tony at CE Auto Electric then I did from MAD. Just my preference.

His books are a cheap investment.

http://www.ceautoelectricsupply.com/wiringbooks.html