5.0stang

iTrader: (1)

I got a "Charging System Failure" a week ago or so and noticed the voltage fluctuating at random times (12.5-15.0) even at a steady cruising RPM.

Battery tested good and I put a brand new alternator on it - and the same symptoms exist.

In my research, I have heard of two things:

1. I saw this post that talks about some sensor that controls voltage from the battery to the alternator?

https://ls1tech.com/forums/ls4-perfo...l#post17871849


You can get the sensor (#5 above) at your GM dealer (I would recommend calling a dealer with your VIN# and getting the latest P/N for your application FIRST)

OR
http://www.rockauto.com/ P/N search 5S6706

Would that be the proper PN for my 2008 GXP?

2. I have seen some say "clean your grounds". I'm electrically challenged - what grounds need to be cleaned?

Can you all provide some guidance. I can see the battery slowly getting drained the longer I drive it (interior lights/displays dimming over time) because it is not being charged properly.

Thanks in advance.

Koren

Try cleaning your connections, the sensor for the gxp I believe should be on the ground wire and also I would sand down the ground connected to the frame. I had to figure mine out myself but I also made new battery connections cause mine were screwed.

also check out he big 3/4 upgrade thread it should have some helpful info

5.0stang

iTrader: (1)

Ok, will do.

Question - does the battery current sensor have to actually be "around" the black battery wires? Why can't it just hang to the side and plug in the new one and break off the old one? I saw some are saying they need to either cut off the black battery wires/cables or loop the current sensor around and off the wires?

Koren

Pm me your email I'll send u a quick vid

5.0stang

iTrader: (1)

Hey, thanks for the offer - I got if figured out (edited the post). It was obvious when I actually went and looked at it, ha.

Question - does the battery current sensor have to actually be "around" the black battery wires? Why can't it just hang to the side and plug in the new one and break off the old one? I saw some are saying they need to either cut off the black battery wires/cables or loop the current sensor around and off the wires?

Here is the part I ordered, which matches what is currently on it:

Koren

Usually that part doesn't go bad lol I would just adjust it on your battery. theres some vids on YouTube I used as a refrence

rottonj

iTrader: (4)

Its a sensor and for sure they go bad. This board is only a fraction of the cars out there with that part, and since there was a change in the part at some point there is a good chance failure had something to do with it.

5.0stang

iTrader: (1)

I replaced the sensor and it didn't fix it.

I did clean up one of the grounds so far by the battery, but the exact same symptoms persist.

Very frustrating...anybody else found a solution?

rottonj

iTrader: (4)

Was the battery load tested and who tested it? Did you replace the belt when you changed the alternator and does it have correct tension? I got that message once from leaving my trunk open and the battery wore down. It didn't come back once the battery charged.

5.0stang

iTrader: (1)

Battery was tested by local auto parts store and mechanci. The belt could be a possibility, but it appears to be in good shape (almost new). Any way to test it or the tensioner?

pdxmotorhead

Is there still a fuseable link or inline breaker in the charging cable on these years? That used to be an issue when the alternator died.... At least on Chevy pickups.

5.0stang

iTrader: (1)

Not that I'm aware of (someone correct me if I'm wrong). The voltage ranges from 12.3-14.5 and seems to not be consistent at all, except is seems to be higher when you first start it and then slowly fades. However, sometimes even after driving for a long time it will randomly start going back up even when "cruising".

rottonj

iTrader: (4)

Is the car leaving you stuck or are you just concerned with the readings?. Those are the same voltages I see in mine and have heard from others, it fluctuates. Mine starts lower and works up, but it is never stable and never has been. I have owned it since 2008. Factory battery then Optima red top in 2012. Its getting time for a new one probably, the car sits a lot and that isn't good for any battery.

5.0stang

iTrader: (1)

Good question - it is not leaving me stuck, but I'm worried about the day it does.

rottonj

iTrader: (4)

This looks like a decent belt. And if it was me and I was worried I would replace the battery. Some don't like Optima and can give good reasons why but I do.

http://www.rockauto.com/en/moreinfo....440277&jsn=385