alternator charging problems.
Thread Starter
Teching In
Joined: May 2007
Posts: 40
Likes: 0
From: So cal.
alternator charging problems. Just finished my swap just recently and while driving the car died and wouldnt start. I later found out my alternator wasnt charging. Thinking it was the alternator i switch it out for a new one. same thing happens. the car wont keep charge. i have one of those battery chargers/testers that tells if the alternator is charging and it says it isnt. It has only one wire that goes on top of the alternator (small red wire). after some reading i found out that this is the exciter wire that should have 12vs. it doesn't.
anyone know whats wrong here? any help is appreciated.
oh yea its an ls1 from a 2002 camaro ss.
anyone know whats wrong here? any help is appreciated.
oh yea its an ls1 from a 2002 camaro ss.
Thread Starter
Teching In
Joined: May 2007
Posts: 40
Likes: 0
From: So cal.
ls1 into a Datsun 280z in my sig.
The harness was reworked by speartech. I have been unsuccessful with contacting them with this problem though. The wire is not getting the 12v it needs.
The harness was reworked by speartech. I have been unsuccessful with contacting them with this problem though. The wire is not getting the 12v it needs.
sorry, i just saw the other thread you had 
nice project by the way!
i'm not 100% positive, but the speartech harness does not come with a plug for the alt. ( if i remeber correctly)
on my mustang i just took the original wire going to the ford alt. and used it for the GM alt.
nice project by the way!
i'm not 100% positive, but the speartech harness does not come with a plug for the alt. ( if i remeber correctly)
on my mustang i just took the original wire going to the ford alt. and used it for the GM alt.
Try running a wire from a switched 12V source to the alternator, but make sure you put a 470 ohm, 1/2 watt, resistor inline before hooking it to the alternator. With straight 12 volts running to the alternator, it won't last long.
i tried the resistor route and it didnt work. so i added a small light bulb i pulled from one of my autometer gauges. ran it in line to the alternator. it started charging right away. my set up is only temporary but here are some pics.
here is the terminal on the alternator
run a bulb in series like this
when you key over the ignition the bulb will light up. when you start the car the light will go out. if your alternator doesnt charge the light will turn on again letting you know. im going to run mine inside the car.
here is the terminal on the alternator
run a bulb in series like this
when you key over the ignition the bulb will light up. when you start the car the light will go out. if your alternator doesnt charge the light will turn on again letting you know. im going to run mine inside the car.
Thread Starter
Teching In
Joined: May 2007
Posts: 40
Likes: 0
From: So cal.
Speartechs replied sent an email to speartech: this is the response.
Speartech <speartech@insightbb.com> wrote:
What you are reading is completely wrong. 12 volts on the red wire will destroy the regulator inside the alternator.
You would need to check continuity of the red wire from the alt. connector back to the PCM connector (PCM RED 15). If that is good the problem is either with the computer or other wiring on your car.
John
Speartech Fuel Injection Systems, Inc.
www.speartech.com
--------------------------------------------------
thing is that when i have it pluged into the pcm like instructed the alternator doesn't hold its charge. what else could be wrong? i alt is brand new.
Speartech <speartech@insightbb.com> wrote:
What you are reading is completely wrong. 12 volts on the red wire will destroy the regulator inside the alternator.
You would need to check continuity of the red wire from the alt. connector back to the PCM connector (PCM RED 15). If that is good the problem is either with the computer or other wiring on your car.
John
Speartech Fuel Injection Systems, Inc.
www.speartech.com
--------------------------------------------------
thing is that when i have it pluged into the pcm like instructed the alternator doesn't hold its charge. what else could be wrong? i alt is brand new.
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Joined: Sep 2004
Posts: 3,148
Likes: 12
From: Downers Grove, IL
If the light never comes on and it has 12V going to it then the problem is with the alternator.
Turn the car to the run position (but don`t start it) the light should be on, if it is not. Then unplug the 4 pin plug from the alternator and ground pin B (the wire that goes to the lightbulb) If the light is still off you are either not getting power or the wire has a break somewhere. If the light lights up the problem is with the alternator, either it is getting a bad ground or is just bad. To see if it is getting a bad ground try grounding the plug to the case of the alternator, if the light is lit the ground is ok, if it is not lit....
Turn the car to the run position (but don`t start it) the light should be on, if it is not. Then unplug the 4 pin plug from the alternator and ground pin B (the wire that goes to the lightbulb) If the light is still off you are either not getting power or the wire has a break somewhere. If the light lights up the problem is with the alternator, either it is getting a bad ground or is just bad. To see if it is getting a bad ground try grounding the plug to the case of the alternator, if the light is lit the ground is ok, if it is not lit....
Thread Starter
Teching In
Joined: May 2007
Posts: 40
Likes: 0
From: So cal.
screw the resistor. i tried so many times to get it to work. just splice in a simple light bulb and be done with it.
i used a spare turn signal pig tail from autozone, then finally settled on a bulb that belongs in an autometer gauge.
i used a spare turn signal pig tail from autozone, then finally settled on a bulb that belongs in an autometer gauge.
