pegged battery gauge.

[Ghostrider 67]

My 08 ram Big Horn, 5.7 Hemi 4x4 with 143,000 mi has suddenly pegged it's battery gauge to the right. I drove it today in a big snow storm and noticed it.
Anyone have any theories why this might be?
Thanks.

 

[65 sporty]

Do you have a volt meter? I would check to see what it's actually putting out

 

[Ghostrider 67]

Yeah, i got one somewhere. I'm waiting for a few days until we have 60+ degrees and full sun here midweek to look at it. I guess what I was asking is is likely to be the voltage regulator or battery or some computer crap that i can't fix?

 

[AJ.]

All the way to the right is overcharge right? Well then either the battery has a high resistance in it, or there is a serious current draw somewhere on the system like shorted auxilliary lights or something, or the regulator sensing wire is open, or the regulator is stuck.
If it cranks ok, the battery is fine ; so probably a regulator issue. If there was a short somewhere, the wire wouldda melted by now and the gauge would be back to normal.
I would not drive it in this condition, cuz it will cook your battery which could then explode.
I do not know how to defeat your regulator. If you do, then you can drive to to the repair shop with the regulator defeated. Alternatively you can unplug the alternator output; just make sure the wire cannot short to anything and remains isolated . You will be running on battery power so hustle..

 

[65 sporty]

I believe the PCM controls the charging, it's the regulator

 

[Ghostrider 67]

Thanks everyone. I live about 5 miles from the dealership so i'll just get it running and unplug it and go.