I am curious how reliable/accurate is the OEM in dash voltmeter for troubelshooting bad batteries and charging system issues? I am not having or noticing any problems, mine has read 13.5 - 14 volts since I got my Cherokee. Just curious if one day it were to drop, does that automatically translate into a new battery, or would a test of the battery condition still be in order?

 

pick up a cheap OHM meter. a device that knows only one thing.... truth. will tell you what your batteries doing on anygiven hood lift.

dash gauges are accurate though

 

They are actually REALLY inaccurate.

More of a 'guess' than anything else.

 

really? how so. what i mean to say is what makes them proned to failure/inaccurate read outs.

 

Here's proof. Mine reads 11.5-12, had me worried so I hooked up a multimeter at the battery then at different fuses inside the jeep. I have around 14v at the battery and at every fuse inside the cab. The gauge runs about 2v low consistently.

 

By OHM meter I assume what some refer to as a multi meter? What about one of the battery tester meters that not only check the battery with and without a load but also the charging system?

 

The readings aren't very accurate. They are general representations of what they 'think' is happening.

They are just very poor quality when it comes to giving info.

 

Would it be fair then to say if one see's a fairly significant decrease or increase in voltage, it is a good sign there is a problem needing to be addressed.

 

From what gauge?

If its factory, I personally wouldn't be super concerned. I would do simple diagnostics so I didn't leave myself a larger mess down the road, but I wouldn't end any important plans because one of my factory needles twitched funny.

 

Mine is about a half a volt off. Which is no problem because with the dash gauge, you're really just looking to see if it runs in approximately the same position. If it is abnormally high or low on the dash gauge, that is when you get out the meter.

ALWAYS use a multimeter when you need diagnostic data points.

Everyone that works on their XJ should own a multimeter and at least a fundamental understanding of how to take a resistance and a voltage reading. WalMart carries inexpensive meters for not much more than $10. Even an inexpensive meter will work okay for most testing. Don't need a $200 Fluke for that.