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Voltage Problem??

852 Views 8 Replies 3 Participants Last post by  Achilles515
99 Wrangler, 4.0 auto. I haven't had a chance to really get into this yet so I'm gonna get some opinions before I tackle my problem. On the way home tonight (only about a 3 mile drive) my check gauge light came on and my voltage gauge was spiked, parked it and shut it off. Came out a few hours later and started it up again and it was fine. I haven't checked it with a meter yet, I'm gonna do it in the morning. Anybody else run into this?
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Sounds me like the voltage regulator in the alternator.
I assumed I'd probably have to get a new alternator, lucky me lol.
Get it tested, but its the likely culprit.
I just tested it with a multimeter. Tested out fine. With the jeep off it tested at 12.56 and with it running it was at 13.89. I turned the lights on and blower on and it went down to 13.66 so everything appears normal there.
That is not an accurate test, you need to have it tested by garage or parts house their machine pursuit under a load. It could be the diodes in the voltage regulator going bad. Which a multimeter went tell you.
Clean your battery terminals with some steel wool or wire brush. Happens to me all the time.
I cleaned my terminals before. I drove it for a few miles trying to get it to spike again, only took like 5 miles then it came back on, pulled into the driveway real quick to test it again (left it running) and right when I went to test it, it fell back to normal. I don't get it lol.
I took the alternator off, went and had it tested, everything checked out fine. Bought some new wire brushes, went through and brushed everything again. Everything looked good but I did it anyway. Hooked it all back up and she's going good now. But I also found a wire dangling which may have hit something while driving and gave a false read somewhere, took care of that as well. Drove it about 20 miles and she seems good to go. Thanks for all the help guys, I'm sure I'll have some more Q's for you experts again lol.
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