I have a 98 xj and I first noticed my voltage just under 14v about a month ago. Im pretty sure it is supposed to be between 14-15v. I doubled checked it with a volt meter to make sure it wasnt just my gage. I replaced the serpentine belt and the tension seems to be good. I have not noticed any other problems from this, lights dont seem to dim or anything, and she still fires right up. Im just not sure if this will hurt anything and if i should just wait for it to die or take it out and get it tested. Any thoughts are appreciated.

 

13.5 is fine. I would be careful about your belt,if it is to tight you can put alot of stress on the bearings of all belt driven components and cause premature failure.

 

check your idler pulley bearing, it could be causing the belt to have friction(possiblilty), just take your belt off and give a little spin

 

If you're worried, compare that KOER voltage reading to the battery resting voltage - alternator output should be at least .5VDC higher.

Battery Resting Voltage - 12.0-12.8VDC (12.6VDC nominal)
Alternator Output Voltage - 13.0-14.5VDC (min. .5VDC higher than battery resting.)

As long as you've got that, you're good to go...

 

Thanks for the advice guys. I checked everything you said as far as belt tension, idler pulley and battery at rest is 12.5v and with the engine running its at 13.5v. If you feel that this is no problem, then that is all I needed to hear. Thanks again!

 

One full volt higher with the engine running? No worries! You're set.

I'll annually back-check my IP voltmeter using a DMM, just to keep it honest. I get something like 14.6VDC at the alternator, 14.55VDC at the battery post, and 12VDC at the IP (that's why I ignore the scale on the gage, and make marks on the window with a grease pencil instead.)