Battery - Alternator HELP

[NASTY08IMPALA 5,000+ posts]

Is 13.6-13.8 really THAT bad? Also can you make a stock alt charge that high too? Or does it always have to be an HO alt to push em that high?

considering i dont drop below 14.4 @full tilt yea its.bad ..and.sure.u should.be able.to get.stock alt that high

 

[gamehawk55 10+ year member]

considering i dont drop below 14.4 @full tilt yea its.bad ..and.sure.u should.be able.to get.stock alt that high

Might have to look into that.

 

[phemps 10+ year member]

the small pulley wont fix.it ..its controlled by the pcm

Actually now that i think of it.. im not using my factory plug i have the new alt wired into ignition switched NOT Controlled by PCM and i have similar issues so i dont see how it could be that...

 

[phemps 10+ year member]

My battery light has been on and i have been having charging issue messages pop up which i assumed was because the new alt doesn't use the factory plug

 

[NASTY08IMPALA 5,000+ posts]

Actually now that i think of it.. im not using my factory plug i have the new alt wired into ignition switched NOT Controlled by PCM and i have similar issues so i dont see how it could be that...

then u have a totaly diff problem

 

---------- Post added at 05:23 AM ---------- Previous post was at 05:22 AM ----------

 

anytime ur.not.usimg the oem plug u will get batt light amd warning messages..mine does

 

[MecaVA]

then u have a totaly diff problem 

---------- Post added at 05:23 AM ---------- Previous post was at 05:22 AM ----------

 

anytime ur.not.usimg the oem plug u will get batt light amd warning messages..mine does

funny i dont have a batt light yet

 

[NASTY08IMPALA 5,000+ posts]

funny i dont have a batt light yet

some manufactures dont.come in at all ..mine.cane on like a week after my ho alt install

 

[NASTY08IMPALA 5,000+ posts]

funny i dont have a batt light yet

what year make and model?

 

[pacustomz 10+ year member]

A high output alt puts out the most amps at high rmp, what you need to understand is a alt will ''shut down'' at certain temps so when you see your voltage drop its because your enginge isn't spinning fast enough to keep it cool to produce the amps. Yes chevy did make alts to be controlled by pcm only to save fuel. I never noticed mine till i did upgrades to my electrical. If your not using the factory plug your alt is "always" on in a sense. What you should do is use a module it will raise the "charge point" of a alt to keep the voltage up even at idle. When it comes to alt and charging everyone has there own opinion and there isn't a common answer since every car is different just read up as much as you can and see what will work in your situation.

 

[09civic 5,000+ posts]

What Mike Singer told me was that when having the smaller pulley, it spins faster when at idle to boost the idle amps.

The problem isn't your PCM, it's because you switched the pulleys.

 

[pacustomz 10+ year member]

What Mike Singer told me was that when having the smaller pulley, it spins faster when at idle to boost the idle amps.
The problem isn't your PCM, it's because you switched the pulleys.

We know its not the PCM since he by passed the harness,so yes it could be the pulley but since your gonna do a smaller pulley make sure you get a smaller belt to prevent slip

 

[cbuts 10+ year member]

We know its not the PCM since he by passed the harness,so yes it could be the pulley but since your gonna do a smaller pulley make sure you get a smaller belt to prevent slip

Mike is telling me its the pulley aswell I got one just short of an inch and I'm going to try that tonight with the small pulley. Hopefully all goes well. My idle should be atleast 14 right? Pretty sûre that's what it was with stock alt

Ok I'm using factory plug aswell no harness nothing

 

[profundus-sanus 10+ year member]

What Mike Singer told me was that when having the smaller pulley, it spins faster when at idle to boost the idle amps.
The problem isn't your PCM, it's because you switched the pulleys.

this is absolutely correct. ^^^

your problem is not your computer, as your computer will not vary alt output by rpm.

If it is the computer all you have to do is turn your headlights on to bypass it. Most pcm regulated alternator gm vehicles have it programmed in to automatically command 14v instead of 12.9 once the headlights are turned on. I'll gladly make a video with my scan tool, 270a singer alt, and my 05 grand prix if anyone wants to argue that.

 

[09civic 5,000+ posts]

Mike is telling me its the pulley aswell I got one just short of an inch and I'm going to try that tonight with the small pulley. Hopefully all goes well. My idle should be atleast 14 right? Pretty sûre that's what it was with stock altOk I'm using factory plug aswell no harness nothing

Aim for 1/2in to 3/4in shorter. Don't go any smaller.

I had to use a 6 groove instead of 7 groove for my car because they didn't make a 7 groove that was the right length.

 

[SounDrive Pro Seller]

Aim for 1/2in to 3/4in shorter. Don't go any smaller.
I had to use a 6 groove instead of 7 groove for my car because they didn't make a 7 groove that was the right length.

I use a stock length belt in mine with no belt slip. It depends on the car though, I suppose some tensioners won't hold the belt as tight as others. Make sure to get a good belt like a Gates or a Gatorback.