macgyver35

I have a weird one. I was out today and as I left the parking lot of a business I had been at for about 10 minutes, I went to accelerate and the XJ sort of bogged down for a few seconds. I let off the gas and then reapplied and it accelerated like normal.

I got a mile from that business and just as I got on the highway, I noticed that the "Check Gauges" light was on. All readings looked normal except the voltage gauge, which was bottomed out at 9 volts.

My thought was that maybe the belt had snapped or something, so I kept my eye on it for a few minutes to see of the temps went up. They didn't. My next thought was that the alternator had bitten the dust. I didn't want to pull over 20 miles from my office in crazy traffic and shut it off because I was worried there wouldn't be enough juice to crank it back up. I decided to stay in the right lane, and if I was running in battery only, just see ho far I could get back to the office before it didn't have enough juice to run the ECM and ignition.

I made it all the way back to the office and it never stumbled or stalled again. I opened the hood with it still running and everything looked normal. I shut it off, waited three seconds, and started it right back up, It cranked just fine and the voltage gauge went right back up to 12. I went inside the office for an hour, and then went to leave to get some lunch.

Same thing. Bogged down as I was leaving the parking lot, then recovered. I went 2 miles down the road to a drive-thru, and as I left that drive-thru and got back up on the highway the "Check Gauges" light came back on and and the voltage gauge bottomed out. I get back to the office, turn it off and right back on, and the voltage gauge goes right back to 12 volts and it runs normally.

I suspect that the voltage regulator may be going bad, and turning the Jeep off and back on is resetting something, but I'd appreciate some feedback.

Battery cables are tight, and I have a 6 month old top of the line $170 Diehard gel cell battery. No other symptoms that I can notice. I have been dealing with a shifting issue in recent weeks with the TC not locking up, but I think that's related to bad shift solenoids and/or solenoid harness.

EDIT: In thinking back over the last few days, my mind latched onto something that may also be worth mentioning. About 2 or 3 days ago, I noticed an electrical whine coming from my radio that was never there before. It's subtle, you only notice it when the radio is at low volume, and it is easily drown out once you turn the radio up, but I don't ever remember it being there before. I have also since stumbled on a post from a few years ago where a guy mentioned similar symptoms and how they all cleared up, including his erratic shifting issues, after he swapped the alternator. I've also had erratic shifting issues for a few weeks.

md21722

When this happens you can try whacking the alternator with a pipe or hammer or whatever you have. If volts come back up, the brushes have probably worn down. You can remove and inspect the brushes. If you can source the brushes you can replace them, otherwise replace the entire alternator.

tjwalker

Very possibly the alternator starting to go south. Especially if it's the original.

I'd refresh all engine grounds (never a bad idea), be sure serpentine belt is tight and not slipping, and if it happens again, it's likely time for a new alternator or find a shop that rebuilds them.

wauto

My wifes 97 was doing the same sort of thing earlier this fall. Ended up being a bad ignition switch. Try adjusting the key when this happens.