Help with a whacky Battery Charge Gauge

[stackz]

1991 explorer:

Ok, for a little while now when I first crank up the explorer in the morning the charge gauge will just go all over the place at idle in neutral or gear and of course the lights will flicker accordingly bright/dim. as soon as you rev the car it will straighten out and then back at idle go crazy again until the car is up to operating temperature.

figured it might be the alternator, so I swapped on another one...didn't fix it. And now its starting to give little flickers sometimes on the highway so its starting to worry me pretty good. Dont need to be halfway between atlanta and charleston and have my charging system go bad on me.

Anyone have a clue what else it could be??

thanks guys!

 

[TheJMan]

My brother's 1993 had a similar problem which was determined to be a loose connection from the positive battery cable to the battery. The voltmeter would dance all over the place, and seemed like it was overcharging. On the throttle it would spike to the right and then settle down around 16-17 volts. Make sure there is no gunky buildup on the battery, and tighten down all your connections.

 

[stackz]

when I first got the vehicle I cleaned all ground contacts and applied di-electric grease at all terminals on the block, battery, etc and replaced the battery terminals. I doubt it's that. Also, while doing this I did check to see if any shielding was cut and didn't see any. I also greased the alternator terminals when I swapped the alternator.

I thought it might have been either the alternator itself (since it was making a noise) or possibly the internal regulator, but as far as I know, the other alternator ruled both of those out so I'm at a loss.

I guess I'll go check the terminals and wires again tomorrow after work. in the meantime anyone else have any other ideas so I can check while I'm out there??

 

[doradexplorer]

I am having a similar problem with my wife's 91 X, reading her helped a little, but no complete solution. To sum up what I have read here:
It could be the battery, alternator, battery cables, charging wire
Any one of them could be the problem.
I have replaced/swapped for known good the following:
battery, alternator, charging wire.
When I replaced the charging wireabout 6 weeks ago, it seemed to solve the problem, until yesterday!!
So now I don't know!!
Scott

 

[Brock94]

Check all the main electrical connections-- wires from battery and alternator at both ends. Don't forget the ground straps too. There are several on the x, but the most important is the one on the back of the engine-- these often get corroded and cause strange electrical problems.