My TJ has the following problem about 1 to 3 times a month.
While driving, the check gauges lights up and the voltmeter gets pegged to the right at 19+ volts! I cycled the key off then back on and the engine died - no ignition lights - no power to the starter. The headlights still work. After 5min or so, everything is back to normal except the radio. The engine starts and I can drive off. I have to reset the radio channels (so I know it saw the 19+ volts)
I checked for corrosion at the battery posts around the alternator and by the fuses but all looked clean.
Because it is so intermittent, I haven't taken it to the dealer as I don't think the problem will show up.
Same here my friend!! no clue what it really is. we are in the same boat.
Last month it happened a lot, this month not at all and always is like that.It has been almost a year since 1rst happend to me.
I dont program my radio anymore.
Sometimes when I'm trying tu turn on the ignition it seems like a death battery but from nowhere I turn the lights on and the power come back again and satart right away.
Mine is a 2000 as well & 4.0
Did you hear something like a bad ground or bad conection on the left side between the firewall and under the dash board???
Each time when it happens, before goes death i heard something like that.
I didn't hear about a ground problem through the firewall but it could be. I have found that turning the headlights on seems to bring the system back and I can then start the engine. Thanks for your reply. Looks like I'm not alone.
I'm glad that works for you, I want to correct 1 thing, the noise come from the passanger side sorry not from the left side.
Well I will keep looking for more answers and will let you now what it really is If I find the answer.
My friend he is a Mechanic and he told me to call him right away if start to fail again ,but like you now since he told me no problems at all hahahahaha.
Btw where are you located Dennis?
Here in FL its pretty Humid specially when the weather changes.
I bealive that is something to do with Water/ Humidity condensation.
theres supposed to be a sensor under the battery that may be the issue. I believe in monitors temp and charge rates. or it could be the regulator on the alternator going out.
No codes at all I did it and it does not give me any code.
It make sense what you just said, because Some times when I’m driving my check gauges light turns on and the Volt needle it’s all the way up.(like a bad Alt. regulator)
But I took it to auto zone and did the battery /alternator thing and the guy told me that everything looks all right the charge was perfect and the battery was ok.
I will take a look to the sensor under the battery this weekend!!
Before change the Alternator.
You know what kind of sensor it is??
I had this problem before. I remeber the one time I tried to jump it because my jeep wouldnt start and it still didnt work. I decided to replace the battery and end terminals for the cables and have not had a problem since I did this. I have a 97 sport.
x2 ^ The regulator on the alt sounds like what's driving the high voltage. If its intermittant, then it may not show up on the test stand. When the reg goes, then you might see small swings on the volt meter that normally aren't there.
I'd suggest cleaning the battery terminals and applying some lithium grease. Its a good practice to do every once in a while, even if visually there is no corrosion evident. Before reattaching the terminals, you might want to let them hang unconnected overnight to reset the computer.
Funny that you mentioned that the headlights work, but the cluster and ignition is out (and only restarts when the headlight is turned on/off?) I read on a forum somewhere that the headlight switch is used to perform the ecu reset on the tj (unplug terminals, connect together to drain caps, ig on, lights on/off, ig off). Or something like that. That's why I'm suggesting reseting your ecu to see if its a matter...
Thanks for the suggestions everyone. I live in Chandler, AZ. The last time I had the problem, it was raining here!
I'll try cleaning the battery terminals and applying some lithium grease. Then I'll let the battery unconnected overnight.
If it happens again, I'll repost.
I had to change My alternator and Battery.
It seems like the volt regulator was bad doing funny things, and killed my battery.
Sinnce I changed Alt and Battery no more Rough idle,no more electrical problems before start everything its 100% right.
This is an older thread, but I am having the same issue now. Since it's only intermittent, my questions is: can I destroy anything by not fixing it right away? Will I fry my electric system if I continue to drive for a little while once the voltmeter jumps to 19+? It has happened about three times in the last month.
And if I do have to fix it: is the regulator separate from the alternator, or do I have to replace the whole alternator? Or is this a whole different issue?
Problem was a short in the battery. Took mine to Autozone and was told it was fine. Went to my mechanic and he found the issue. New battery and no issues now. He also tested the rest of my electrical system to make sure the alternator was ok.
well I'm having this problem now. the last time it sat for 3 hours dead. then I disconected the battery postive post, nothing. then I disconnected the negitive post. let sit for 5 min. hooked it back up and she was good to go..
on mine I could turn the switch on and got nothing, no dash lights no nothing, then turn off and the dash gauges would bounce and something click every 5 seconds or so. sometimes just a time or two and sometimes several times.
but the negitive post disconected reset something and she was good to go then.
but still dont know what caused it.. battery reads 14volts constant.
I just started having this problem. I installed a new alternator three weeks ago and everything appeared fine until today. The Jeep fires up ok, then after 4 minutes the volt meter spikes to 19+. By the time I get got to check with a volt meter it has dropped back to 14 though.
I know I am in desperate need of a tune up as I am gettin g back fires under load.
Ok I'm a newb but I read somewhere that the voltage spike may be caused by a bad ignition coil. Does anyone know if that is true and if a new coil may solve my back fire issue as well?
1998 Wrangler TJ Sport
2010 Colnago World Cup