Service Charging System Light?

15002NV · March 5, 2009

My tuck now has the Service Charging system light on. After I installed a dual battery system. Can the code be cleared? As I don't want to replace the alternator.

Note this is not the factory style dual battery system. It has a battery isolator. Optima runs radio,alarm,hids and amps.

Thanks

redvett · March 5, 2009

Fix your electrical problem with the isolator and the light will go off by its self.

My tuck now has the Service Charging system light on. After I installed a dual battery system. Can the code be cleared? As I don't want to replace the alternator.

Note this is not the factory style dual battery system. It has a battery isolator. Optima runs radio,alarm,hids and amps.

Thanks

15002NV · March 5, 2009

Fix your electrical problem with the isolator and the light will go off by its self.

My tuck now has the Service Charging system light on. After I installed a dual battery system. Can the code be cleared? As I don't want to replace the alternator.

Note this is not the factory style dual battery system. It has a battery isolator. Optima runs radio,alarm,hids and amps.

Thanks

I don't have a problem with the isolator! As far as I know. I have 1/0ga wire from alt. to center post on isolator and then 4ga to each battery.

Are you saying the New trucks some how see voltage at the factory battery and the alt. and if it is different it will throw a code? If so a Isolator will always have a problem. I will have to have a dual battery non isolated system.

Thanks

15002NV · March 5, 2009

Wow you where right as soon as I rebolted the factory power wire back to the alt. and it worked right away.

So new question can it be programed to work my way?

Thanks

redvett · March 6, 2009

The wire on the terminal post at the alt. must be there, i would check with the company of the isolator correct wiring.

Wow you where right as soon as I rebolted the factory power wire back to the alt. and it worked right away.

So new question can it be programed to work my way?

Thanks

15002NV · March 6, 2009

There must be a drop in voltage on the number 2 post. I will have to try changing the number one wire to the number 2 post. Or check everthing with the DVM.

It was showing 11.5V on the gauge in the truck. And when returned back to stock it shows 14V. There can't be that much drop in 2ft of 4ga cable. It must be in the isolator.

15002NV · March 8, 2009

Ok something I should have read up on but GM has a sense wire on the alt. plug. If it doesn't see a good voltage it tells the truck the alt. is bad. Or in are truck it ups the output. So anyone be so kind to help me out with what wire in the plug it is? I talked to the company I bought the isolator from and it is a super easy fix. A 2" jumper of the 1# main post to the sense wire. As a diode isolator will have a .2-.4v drop from alt. post to 1# and 2# post.

And the alt. is puting out a 14V charge but seeing nothing or 12V at best.

My isolator doesn't have the sense output but it is ok I can still do it. and it was very expensive as I will make it work.

There has to be a GM tech around here! Thanks