Did I wire my One wire Alternator correctly

rbray · #1 (**permalink**) 03-25-2007, 02:06 PM

Okay this sounds like a stupid question, but over the years I have made lots of dumb electrical mistakes.
Here is my latest adventure.
I installed a one wire alternator and ran a wire form the terminal on the alt to a high amp circut breaker and form the breaker to the postive terminal on the battery.

Does this sound right?
Thanks,
Roger

lineslinger · #2 (**permalink**) 03-25-2007, 03:21 PM

In here there is no such thing as a stupid question, those are reserved for wives and teenagers.
Your one wire alternator has an internal voltage regulator. I don't see anything wrong with your setup as long as your breaker can handle the amperage output from the regulator. You didn't state the amperage rating of the breaker or the brand of alternator.. With the way you have it configured your breaker will act as a surge protector helping to protect the battery from excess voltage should the regulator in your alternator go haywire.
If your breaker trips you should get a low/no charge indicator on the dash if indeed you have such an indicator on your instrument cluster. If not you will know soon enough as the battery will get drained without a charging current.

rbray · #3 (**permalink**) 03-25-2007, 03:43 PM

Hi Linelinger,
Thanks for the feed back. I just fired up the car and the breaker didn't trip.
Here goes the next question.
I have a SW Volt gauge. How do I wire this into the system so it can read if I'm charging or draining the battery.

Thanks again,
Roger

lineslinger · #4 (**permalink**) 03-25-2007, 04:10 PM

rbray,
Without being able to see how your system is configured I think it would be ill advised of me to offer a formula as to how it should be wired up.
USUALLY there is a lead coming off either the alternator or the battery or both which can/might/should be designated for a low voltage indicator light or a charging/voltage meter mounted on the dash.
Do you have a schematic drawing of your cars electrical system or maybe the gauge has some decent instructions?
Different systems use different routing for the indicators/gauge. Some will run a separate lead from the alternator to the gauge, others will run from the hot lead of the battery to the gauge while others will have the gauge wired in line between the battery and alternator.
See if you can't search the EM guys on this site and maybe someone will offer up their wiring schematics.
Sorry I couldn't help more, but misinformation from my end could result in melted insulation or worse on your end.
Good Luck.

trularin · #5 (**permalink**) 03-25-2007, 04:26 PM

Marks right...wives and teenagers.

Velox · #6 (**permalink**) 03-25-2007, 04:33 PM

Quote:

Originally Posted by rbray

Hi Linelinger,
Thanks for the feed back. I just fired up the car and the breaker didn't trip.
Here goes the next question.
I have a SW Volt gauge. How do I wire this into the system so it can read if I'm charging or draining the battery.

Thanks again,
Roger

Hi Roger, I wired up my system with a voltage gauge, they are just a basic voltmeter, ground (negative) side goes to chassis (metal) source (assuming your car is a neg ground system) and positive (+12V) side goes to a battery source. It will read the voltage of the system from anywhere, it just depends on how accurate you want it to be and how you want it to function. For example, the most accurate charging voltage would be to run the 12V+ side of the voltmeter directly to the + alternator post (the one that goes to your breaker) and this would read what your alternator is putting out voltage wise at any time. The most accurate read of what voltage is being sent to your battery would be to wire the + side of the voltmeter directly to the battery. The problem with those systems is that it leaves your voltmeter "on" all the time, always reading system voltage, unless you have a safety switch on your battery to disconnect it when not using the car. I wired my voltmeter up to a 12+ source that was only on with the ignition in "run" position (easily found by using a test light and checking the terminals on the ignition switch or sources on the fuse board) but this won't give the most accurate charging voltage as will be reduced somewhat by whatever is "on" on the main car cicuits - lights, heater etc. "Charging" will be obvious from the voltmeter indicating higher system voltage than what the battery puts out with the car off, usually 14.5V or so. Charging failure would be indicated by a lesser system voltage than what the battery should have available, i.e. less than 12V. Just because the system is sending 14.5V to the battery doesn't mean the battery is accepting the charge... This gets into the entire ammeter vs voltmeter discussion, alot like the BBF vs SBF discussions. Personally I much prefer monitoring my voltmeter, just my 2c worth

jwd · #7 (**permalink**) 03-25-2007, 05:18 PM

Quote:

Originally Posted by lineslinger

rbray,
USUALLY there is a lead coming off either the alternator or the battery or both which can/might/should be designated for a low voltage indicator light or a charging/voltage meter mounted on the dash.

Not with a 1 wire alternator. That's why I would never use one. Here's a link that tells the whole story about 1 wire alts. and the problems you'll run into if you run one.
http://www.madelectrical.com/electri...hreewire.shtml

I've always run a 3 wire with remote voltage sensor wire. Always a fully charged battery, bright lights and correctly operating accessories.

Thomas Gayer · #8 (**permalink**) 06-16-2007, 06:54 AM

I have a one wire setup on both of my hot rods and it works flawlessly.
It's simple , clean and eliminates a bunch of wires.
You would be MAD as a hatter to install all those other wires.
Of all my drawings for wiring it is the simplest, one wire.
Good luck with your project.

Tommy