Lane Hoover

I own a 95' Cherokee XJ, I have been getting occasional Battery voltage gauge readings in the cluster that are below spec, it happens in cold/wet weather mostly and sometimes on dry and warm days.
Other times it runs fine like nothing ever happened. I replaced the battery and ran a DMM test to the alternator and it wasn't putting out enough voltage to charge the battery.
But when it works normally everything checks out and the alternator is up to spec and everything runs fine.
Anyone have any idea why it inconsistently runs right and doesn't?

Roler

Having some trouble making sense out of your info (but that might be me)
So do you mean the battery gauge gives inconsistent readings, or is it that your jeep runs bad at times and on those occasions you notice the battery gauge reads lower voltage?

agreen

The alternator is nothing more than a belt driven AC generator that has a rectified and regulated output. That means it has brushes inside that ride on a slip ring. The brushes will wear out over time. Sometimes when they get some years on them, they'll start sticking in their brush boxes. This means they won't make contact with the slip ring, and the alternator output goes low.

In a nutshell, you should probably replace your alternator. You can opt for a bigger one, or stick with the stock 90a unit if you don't want to modify your existing bracket and wiring.

Lane Hoover

Both, At the times the battery reads low is when it runs bad. But then it shoots back to normal and everything runs fine.

awg

unless you have a bad connector, or ground, there is only 2 real alternatives,

Alternator & PCM (as it regulates the voltage)

From the experience of myself and others, I would replace the Alternator without further ado (after checking wiring)

I buy them used for $50