Well I Had 9 Red Tops In My Van, And I Could Hold 13+ Volts For 45 Seconds At Full Volume - It Started At 14.3 And Slowly Decreased, In Spl Contest 30 Seconds Is All You Needed - I Could Play That System All Day And Never Have A Problem (alway Had Engine Running With 2 200 Amp Alts), Voltage Would Settle At 12.5 -

 

what gauge wire is recommended and got anymore detail on upping the voltage??

it is an old alt....its all goin on a 91 cherokee if that helps

 

A stock alternator will never fully utilize a 4ga wire - which can handle something like 500 amps/ft you can always go bigger like 0/1 ga for overkill but you wont see any dramatic improvements. The battery to ground wire is a different story. You want this as big as you can possibly get it. Since that wire grounds everything in your car, its usually the biggest throttle point for current flow.

as for the regulator,
it depends on the alternator - Mine has a two pin plug attached to it. One will send ground when the voltage is low(like 10 or 11 volts) to the alternator warning light the other is a Vsense wire that measures the voltage and increases or reduces the regulator's voltage level.

By adding a resistor inline with this wire, you present a voltage drop effectively fooling the alternator into thinking the voltage is lower than it actually is. The alternator assumes theres a large draw and throttles the generator to its higher output.

The reason I say only do it to an old alternator is that it will shorten the life of the alternator considerably. Also make sure you experiment with the resistance - an alternator is capable of outputting extremely high voltages. Ive gotten mine up to 18 volts before I got scared and turned it down. That kind of voltage could burn out a pcm and possibly damage firing coils etc...

 

I say use the biggest wire you can fit, within reason (1/0), for all of the big 3 upgrades. Cost difference over such short distances is negligable, and by using bigger wire, you only have to do this upgrade once, instead of each time you upgrade something else.

Also, fwiw, Dalton is slightly incorrect in his description of the alternator wires. One is, in fact, the voltage sense lead. The other, however, does not 'send a ground'. The second wire is actually at the same voltage potential as the output of the alternator. One end is terminated there, the other runs into the car, through the alternator light, and on to the ignition power buss of the car. As long as the voltage at this bus and the alternator output are the same, no current flows, and the light stays out. If your alternator goes out, or the output voltage drops off however, the higher voltage at the ignition buss will feed power through the light, to the alternator, causing the bulb to come on.

So, other than pointing out a Dalton mistake, why did I bother to post this? Well, the light can also come on if the voltage on the alternator is higher than the ignition buss as well...current will flow the other way, and the bulb doesn't know the difference. This can happen if you use isolator diodes, or if you have a loose or otherwise poor connection between your alternator and your vehicle electrical system.

I like the idea of the resistor on the other lead. In fact, I think it might have been my idea, at some point . I'd be interested in any data people gather on this. For a milder approach, I've also thought of extending that wire, and connecting it at the power input of the amp. That way, the alternator sees the voltage right at the amp, and will try to maintain it to the setpoint.

I also believe this would be a good way to overcome the 0.7 volt drop inherent to isolation diodes.

Toby

 

I'm glad theres someone here smarter than me, I actually get to learn something. Do you have a wiring diagram so I can understand exactly how the light works as im still a little confused.

 

You'll probably feel even dumber when you see this. Rember current flows from high potential to low potential. While ground is the ultimate example of low potential, it is not the only one.

ign buss-------------bulb--------------alternator

one end of the wire is on the ign buss of the car, the other is on the voltage regulator in the alternator. Here, it is isolated from the output terminal on the alternator, and sees the voltage at the stator

as long as the potential at the ign buss approx. equals the potential at the alternator, no current flows, no light.

If the alternator starts to fail, and say, puts out only 9v, the potential at the ign buss will be greater (still at 12+, due to the battery), and current will flow toward the alternator, lighting the bulb.

Or, if say the cable between the alternator and the battery were to come loose, the alternator would be the higher potential, and current would flow toward the ign buss, again lighting the light.

Or, if the regulator were to go south, and the alternator started putting out 15v, the light would light.

Its also worth noting that on many alternators, the connection through the bulb is required, as it brings the initial 12v to turn on the regulator.

Toby

 

- a one wire alt jumps the wire interally to turn on the rectifier/bridge and elimates the external wiring all togethe.

 

ahhhh i see the light. literally.

 

Correct, sort of. A one wire is called a self exciting alternator, and has a voltage regulator that senses the residual magnitism in the stator to know when the alternator is turning. The rectifier bridge is just a bunch of diodes, and doesn't 'turn on'. Usually, this type of alternator requires you to rev the engine slightly to get it to turn on. They are rarely, used in any factory applications...they are primarily for aftermarket use, in motor swaps, hot rods, etc. Actually, I can't think of any factory installed one wires, but I don't like to say 'never'.

Toby

 

so when ever i get my new alt...and finish my big 3....what kenetik battery should i go with? i see that they make a bunch of different ones