My question was how many terminals are on the switch? As I said, most Taylor switches only have two. Your drawing shows three. Was trying to figure out what the alternator was connected to. And the readings make no sense still. Go back to the trunk and find a good ground. On my 2003 Mustang I could not and had to run a wire from the negative side of battery. Read the voltages again with the engine running. Battery, alternator and switch all to a good ground.

Al 95 Z28

 

Where's did you purchase you alternator?

 

The switch is a 2 post switch. The alt and battery are on one side and then the power wire for the rest of the car is on the other. The readings might not make since but that's what they where when I tested it. How do you suggest I go about grounding the switch and ALT. They dont have a ground post on them. The Alt grounds through the bracket and motor from what i've read. As for the battery ground I can redo that ground however it is on bare metal and several folks have ran it to the same exact location. Hell I'll try anything at this point!
I got the Alt from Autozone. It was under warranty from when I purchased it back in 2006, so therefore they gave me another for free, and then another lol!

 

Ok, there are a few things to understand about batteries and alternators...

First off the battery is actually part of the charging circuit. It is not just the repository, it is actually part of the charging circuit itself as it acts like a giant capacitor. The voltage off your alternator is not perfect DC, it is far from it. Once you have things start going bad inside the alternator (such as parts of the rectifier or the regulator) you can have even worse DC or even a form of AC start coming from the alternator. Point is the entire electrical system of the car expects to see perfect DC and it does that because the battery itself smooths things out and allows everything to "see" perfect DC.

If you look at any charging circuit from any manufacturer you will notice the alternator connects to the battery, or to the largest gauge wire the closest to the battery as possible. That is so the battery can smooth out the DC waveform before it goes to the rest of the electrical system as well as making sure the battery charges before current is drained off by anything else in the electrical system as well. It is ESSENTIAL that the battery is the first stop for the current coming from the alternator IN ALL CASES! Try running any modern car off only the alternator and be prepared to start replacing things that will just "magically" go bad. The battery is a requirement. Alternators can die and you can run everything off a battery until the output drops too low.

So, simply, to fix your problem you should run a seperate 2 gauge wire from the alternator to the battery and then another 0-gauge wire from the battery to the terminal up front and from there directly to the starter and whatever else you need. you can also tap off the relocated battery directly for anything else in back, or run a seperate 2-gauge wire to the starter directly from the battery. Key is you need the alternator hooked up directly to the battery first, then you can distribute from there as you need to. There is no shortcut here and people always bitch about battery relocation not working because they don't follow the same exact current path as originally designed into the stock power harness.

It would also not hurt to run a seperate 0-gauge ground wire from the grounding location on the front fender to where you ground the battery in the back. It will get rid of any ground potential issues with relying upon the chassis for proper grounding.

I have run relocated batteries as well as big stereos with multiple batteries. My T/A has a starting battery up front, a deep-cycle battery for the stereo in back (isolated by a 300amp relay to make sure it isn't connected unless the car is already running) and a 250amp dual-rectifier alternator. All connected with 0-gauge wiring throughout to both the alternator, the batterie(s) the starter and the power distribution blocks. My Z28 'vert has a single battery in the stock location, 0-gauge power and ground wire for the amps in back, a 250amp dual rectifier alternator as well as 2-gauge wiring from the alternator to battery, the battery to power distribution block and the battery to the starter. I have zero charging issues throughout.

I have seen how bad alternators can get as well as I had major issues with getting a setup running properly and consistantly. New motor, new everything, car wouldn't run the same all the time. Battery voltage was good, had all new 4-gauge wiring from the alternator to the battery. Tested the alternator, said it was fine. Turns out the alternator had a bad regulator and had a marginal rectifier issue. Only became a problem when hot. Well, it was so bad it basically caused so much bad output it caused the wire at the battery terminal to overheat and heat-fatigue and fail. It also caused an "electrical cavitation" with the rotor/stator inside that was giving a nasty vibration that was hard to pinpoint (thought it was something with the engine itself). Wasn't until the wire from the alternator to the battery failed completely (literally looked like someone took a blow-torch to the strands of wire at the terminal) that I repalced the alternator. Once that was repalced and a new 4-gauge wire put from the alternator to the battery did all the issues just disappear. Engine ran smooth with full power all the time, consistant as it should be. Battery was severly damaged and it would not charge properly in or out of the car, so it was replaced and the new one charged just perfectly. Point is that all parts of the primary electrical power supply of the car (battery, alternator, main wiring and grounding points) are all required for things to work as they should. I keep on hand an extra "known good" stock 140amp alternator, stock main power and ground harness, a stock unmolested MAF sensor, known good IAT, known good MAP sensor and a couple of known good O2 sensors as well (these have the ugly internal high-pitched ringing to them when the engine is running, but they read perfectly) all just to help diagnose and troubleshoot things. Didn't really think I needed an alternator in the "known good" test parts bin, but a few months of hell changed my mind on that.

 

95 TA,
All sounds good, however. If i hook the Alt directly to the battery then the car will not shutoff with the switch. What's suggested now?

 

Get rid of the switch.

Honestly, if you connect the alternator directly to the battery first why would it affect anything else?

Why do you want a kill switch?

Unless it is for racing and located on the rear bumper then it serves no valid purpose. Even if you run it back there the battery being directly hooked up to the alternator should affect nothing else as the power feed line can go through the cutoff before anything else on the car.

Alternator - 2-gauge - Battery - 0-gauge - switch - 0-gauge - rest of the car (starter/power distribution/etc)

Just so you know, everytime you pull power from everything it is basically resetting the PCM learns and everything else.

You *CAN* run the cutoff switch at the back if you really need to (ie for racing) and to properly do that run the 2-gauge alternator wire and the 0-gauge power feed to one side of the switch and a 0-gauge wire from the other side to the battery. You need to make sure the switch is mounted as close to the battery as possible. Not ideal but the switch will then fully remove the battery from the equation when you flip it. That is the idea, to fully remove power in event of a crash, ie nothing left to spark to start a fire.

Also, race cars that require cutoff switches are NOT street cars, thus charging and everything else is usually less than ideal since it isn't a consideration. Plenty of racers run 0-gauge to teh switch in back and then to the battery in back with no special consideration for proper charging with a seperate alternator wire to the battery.

 

Also, I relooked at the diagram you posted and connecting the alternator directly to the battery in the back on a seperate wire is no different than what you posted in the picture, so, again, your comment doesn't make much sense in regards to the car not shutting off with the switch.

 

The car will never shut off with the switch if the alternator can power the car. And the rules say "kill all power to the car." Not kill everything EXCEPT the alternator. A live wire to the alternator with the switch off is against the rules.

The point? 4 terminal switch is the only right way to do it. But there I go repeating my self again....

http://www.saferacer.com/longacre-ba...?productid=611

Al 95 Z28

 

Like I said before, alternator to the battery and then the kill switch on teh wire form teh battery to everything else. You cut the power coming from the battery/alternator and it is all disconnected. Yes you need a seperate circuit for killing the alternator to the battery, thus the 4 terminal you linked is the all-around kill solution. Key point is it has to be as close to the battery as possible to keep the charging proper as I mentioned.

Again, per the picture he posted at the start of the thread, there is no reason to NOT run the alternator to the battery directly. But you are correct, that picture is wrong on many levels in regards to a racing kill switch.

 

Battery cut-off switch + PITA = Ditch it.

Unless you are entering NHRA ruled events...its over kill.

 

Thanks big al, yeah the alt wouldn't turn off directly hooked to the battery in return the car wouldn't turn off. I pretty much wired it exactly like others off here. Not sure whats so wrong with it, minus charging issue. As for the switch I can try a 4 post switch. I would hate for anyones battery to be dead our needing swapped out. Killing the power is a no no on street cars. As far as this thought, its not like its gonna drop the tune if thats what your implying.. I have a few different test I'm gonna try out and ill let you all know what I find out. Most likely this weekend, busy this week. Good thing about having 3 vehicles, it can sit. Thanks for the help

 

What the hell are you talking about that the alternator would not shut off hooked directly up to the battery???

You do realize that the alternator is ALWAYS hooked directly up to the battery via the large-gauge wire. That is on not only stock power harnesses, but also "per your diagram". Only the small 16-gauge red wire on the plug on the back is controlled via the PCM to "turn on" the alternators regulator when the car finally starts.

Talking to people around here is like talking to a wall. They don't care to think about what they are saying and refuse to even try to listen to what others are saying.

If you don't need a cutoff switch, then don't wire in a cutoff switch. It is that simple.

 

Wonderful post, but you missed the point. If the alternator is hooked to the "car" side of the switch the car won't shut off when the NHRA tech inspector turns the kill switch off. The kill switch is a safety device that kills the car and shuts down the engine. It's different when you turn off the ignition switch.

If the alternator is hooked to the other side of the kill switch, call it the "battery" side, the alternator will have 12 volts to it with the kill switch off. Most tech inspectors won't catch this, but it's wrong.

Notice I didn't attack you or treat you like a "wall." This is a forum to try help people.

Al

 

95 TA - The Beast is correct.
The alternator can be hooked directly to the battery + with no issues.
It doesn't matter if the alternator gets battery power when you turn off the kill switch, because everything else on the car gets power from the battery, not from the alternator.
I have it hooked that way and it kills the car when the kill-switch is turned off.

If you need to cut ALL power, you need a switch with alternator disconnect circuit (4 terminal). This kind of switch lets you hook the alternator directly to battery and still cut all power when needed.
http://static.summitracing.com/globa...74102_inst.pdf

With a 2 terminal switch you need to hook alternator directly to battery (without any means to disconnect it). If you hook the alternator to anywhere else, you may have issues.

 

My god, this has turned into a pissing match. Not sure why the simple solution keeps resorting back to getting rid of the switch. Question for you, if the battery is in the back and you enter the ltx shootout, is tech inspection accomplished? If so then yes I will need the switch. Totally off subject but it seems like I have to have a reason here for the switch. I just want it hooked up correctly and my **** to charge correctly. Sounds like the 4 post switch may be the right direction to start with.

No reason to get angry. Its a forum with folks looking to get questions answered and advice on hicups they may encounter along the way. If your just going to get pissed off why try and help.

 

You are missing the point... It is frustrating when you go through all the time to fully explain EVERYTHING in detail and have people ignore it and ask the same question or reach the wrong same conclusion over and over when you have covered it in detail.

 

He is saying run a wire from the alternator to the battery then from the battery to one side of the switch. This puts both the alternator and battery on one side of the switch. On the other side of the switch, run a wire to the starter post. Then from there run a wire to the positive terminal post on the passenger side. Your grounds should be as big as your power. I got 1/0 cable off of ebay. Its the good **** the crazy stereo guys use, google around and see what they use. I am assuming you are having a large voltage drop across the wire. I have had absolutely no issue with my relocation and a summit brand 2 terminal switch.

 

Well took a good break from the car and got back to it. So I did what was posted. I ran the Alt wire directly to the battery,+ side. Then from the battery to the switch. I then ran from the other side of the switch directly to the starter, off the starter to the rest of the + leads located up front. Needless to say I have yet to take it for a drive all though my ALT is now squealing like crazy again like the bearings are shot again until its warmed up. I let it run for about 30 minutes outside the house, killed it with the switch which is still functional and went to go fire it up and the volts where low and it barely wanted to start. Oh yeah I just swapped out the battery for another brand new yellow top with top mounts for ease. Back to the drawing board I guess.

One new peice of info I found, My stereo face plate lights up in the car if I flip the kill switch a few times. It goes off when you open the door. I know the stereo has a constant power however not sure if it should pop on when cycling the kill switch a few times and returning back to ON. I have my AEM wideband tapped into the radio power wire for a power source so it comes on as well..... Like I said they both go right out when I open the door. Any thoughts to this?????

 

This is how I have my car and everything works just fine. Switch kills power to entire car, alternator charges just fine, and has had no question at 2 years of tech at NHRA tracks and NMCA events where they crawl under the car and look at EVERYTHING!!! Using a 2 post Taylor switch.

 

Ok so did some testing tonight, come to find out car not started reads 12.4,starts up charges to 14.4 which is great all though the alt still squeals. After more testing we read that there is a perfect flow until we get to the starter which drops when starting from 12.4 down to 9.1 when starting which is taking alot to get it to turn over. Weird part is my buddy rebuilt it as a high torque about 8 months ago. Is this the problem it's taking so much to crank it over? It seems to be charging however it's a bitch to start even after starting or during at a point. Any thoughts?