funina91ss

I posted this here because it is a drag racing mod. but I ran 2 guage wire from the battery to the switch then from the switch to the postive cable under the hood and spliced(soldered) into the stock wires.then I ran 4 guage Amp wire (audio wire small strands)From the alt. to the + side of the battery.pics of install I have an optima red top 700 CCA My voltage stays at 12.0 with the car running. any ideas?

Stephen 87 IROC

The alternator needs 2 feed wires. The larger wire, usually 8 or 10 gauge, goes to the hot battery post. A smaller wire, 12 or 14 gauge is needed for the field windings. Without it, the alternator won't charge.

If you loop a wire from the battery feed side to the field windings, the alternator should charge however turning off the master switch won't kill the engine because it doesn't disconnect the field wire. The alternator will just feed itself.

funina91ss

I am not sure what you are trying to say my alt. only had one power wire going to it it was spliting off from the + of the factory battery location . where am I supose to run this other wire from?Thanks for the info I just need more

Stephen 87 IROC

Hmmm. You haven't changed anything except the main power wire coming off the alternater. There's a harness plug going to the alternator. There can be anywhere from 1 to 4 wires on it depending on the model of the alternator. I'm not sure where the factory harness gets it's field wire power from.

If you can, see if a small screwdriver will stick to the center of the back of the alternator while it's running. When an alternator is charging it creates a magnetic field and the screwdriver will stick. It's not much of a magnetic field but it's still there.

My guess is that the alternator is dead. Pull it off and have it tested.

IrocSS85

yeah, sounds like the alt. isnt working for some reason. I did this mod to both of my cars. the Iroc got 1 awt wire that is welding cable (which is very fine strands that had no voltage drop the entire length of 22 feet) and that one is perfect. no troubles. the 95 Z got a summit kit that has 2 gauge wire from the batt. to the starter, like the stock batt. wire. then I left the stock cables in place (but obviously disconnected) this car has a problem some times not cranking when I go to start it. it just clicks. the starter and batt. are fine. when I reinstalled the batt. upfront, the prob. went away, so I put a bigger batt. in the back and its much better, but still does it once in a while.

anyways, there's no reason that should cause the alt. not to charge. did you disconnect anything else when doin this? are you sure? double check for any wires you left off. esp. the connector on the back of the alternator and the post. make sure the small 14 gauge wire has power on it also when the key is on.
chris

GUMP

On my cars you have to put a small resistance on one of the pins on the back of the alternater for it to charge. I have a 12V bulb connected betwean it and ground. Just can't tell you off the top of my head which pin it is! (The light will go out when the alternator is charging).
Any auto electric shop should be able to help you.

Daren

funina91ss

I didnt cut any wires going to the alt. all I did was run a 4 ga. wire from the output of the alt. to the battery and the 2ga. from the battery to the stock + cabels I just spliced them together.

Nostang 96z

Here's how I wired mine. I used a kit from Ron Francis wire works. I ran 0 gauge cable from the red hot box under the hood on the passenger side to the starter + to the back of the car to the + side of the shutoff switch then from the shutoff switch to the + of the battery. Next I ran a 0 guage ground from the starter bolt all the way back to the - side of the battery. I also grounded my battery to the frame in the back of the car with a 4 gauge wire and ran a ground from my engine block to a ground on the passenger side fender well that was used for other wiring already from the factory. Lastl,y I ran fine 4 ga wire from my alt all the way back to the positive side of the battery. I've had no problems whatsoever with my charging.
Later
Matt

ssdungeon

Use a 200 amp relay It will keep the charge constant. about 40 bucks. Its needed if you have amplifiers... large amplifires in the trunk with the battery.