92 cherokee electrical problems

I'm having some electrical issues with my 92. I've got a check engine light that comes on intermittently. The code is ENG: 41 charging system CKT/ALT field CKT. My dash guage voltage fluctuates from 9 to 14. My headlights, dash lights wipers etc... all dim/slowdown when the voltage dips. I'm thinking that this is probably an alternator problem but I'm wondering if the battery or the voltage regulator could be the culprit. Thanks.

Could be alternator, or maybe voltage regulator, the computer, the battery or even corroded battery cables.

Might pay to get a voltage tester and see what the voltages are at the battery and on the alternator. That's where I'd start.

Don't rely on the dash gages. Get a voltmeter for testing the battery and chargining system. The dash gages are prone to erratic readings.

I have posted some electrical testing techniques previously.

An analog (with the needle in the window) volt-meter will show fluctuations more quickly/accuarately than todays more predominant digital flavors. Analog meters are commonly used at aftermarket car-stereo shops for troubleshooting electriacal issues. I actually missed that question on the test trying to get a job at a local shop... meh.

I've had the charging sys tested at the local auto parts store and the voltage at the time was way low (9 volts). What does the little black box that is on the alternator connections have in it? I tapped on it with a screwdriver, the alternator kicked in and the voltage went to normal (14 volts). I tightened the connections on the alternator but that didn't help.

I've had the charging sys tested at the local auto parts store and the voltage at the time was way low (9 volts). What does the little black box that is on the alternator connections have in it? I tapped on it with a screwdriver, the alternator kicked in and the voltage went to normal (14 volts). I tightened the connections on the alternator but that didn't help.
I don't really know what it is or what it's called, but if it changed by you tapping on it, I would imagine it's got connectors in it with bad connections. Open it and see. if there are contacts inside, clean or replace them.

Advice can point the way, nuts need breaking, but work needs a steady hand! lol :popcorn:

~Good Luck

Here's a quick but late update in case some poor soul has similar problems and is doing a search for help. I replaced the alternator and all is well. It seems the alternator had a ground in it (intermittent but gradually worsening). Thanks to all for the replies and advise.