Help Needed!

[SDH281]

Alright. I don't post on here very often, but I am having some trouble with the XJ and thought you guys might be able to help. Yesterday morning, I went outside to start it and it was like the electrical system was completely dead. No lights, no radio, no beeping, and nothing at all when I turned the key. I decided to take my wife's car and run my errands for the day and fool with it when I got home. So, last night, I got in it again. This time, the interior light came on and when I put the key in, it acted like everything was normal. However, I turned the key and it started strong, but then died out. I tried again and gave it some gas and actually kept it running. While it was running, I could hear a loud whining/moaning coming from what sounded like the front passenger side. As soon as I took my foot off of the gas, it died. Anybody have any theories? Until I can get my buddy to help me out, I can't track down the noise any better. Any help is greatly appreciated!

 

[dave92cherokee]

For the electrical problem I'd first start by checking every power connection under the hood for any looseness or corrosion and tighten/clean as necessary. For the loud whining problem coming from the passenger side, it could possibly be the alternator going out. Which if it is on it's way out combined with loose/corroded connection to the battery could cause it to die as it's not maintaining the 12v that the engine needs to run.

 

[SDH281]

Thanks Dave, I will start down that trail!

 

[UNCC_99XJ]

I agree with Dave on the alternator, sounds like it's not happy and may be getting ready to play dead.

First thing I would do is clean the battery connections very well. I had the exact same thing happen one time on my Jeep. Got in, and everything was dead...no lights, no nothing. Tried it again a few minutes later after touching absolutely nothing, and it fired but wouldn't stay running unless I kept my foot on it. This is because the computer had basically done a reset, and needed to relearn it's parameters, including how to idle. I've had the computer do that several times before if I leave the battery disconnected for a few days or so. Cleaning the connections at the battery and double checking all the other grounds took care of that no-start issue.

 

[SDH281]

Thanks UNCC!

 

[SDH281]

Update. Just went outside to fool with it. Battery cables are tight. Although, there is an area that is somewhat frayed. I tried to start it and it fired right up. It is sitting right now idling fine. Volts, oil pressure, and temp all look good. No more moan/whine coming from the passenger side. It is throwing a CEL and I don't have a scanner to read it with. I'm going to drive it to my buddy's shop and see if we can figure this out. I appreciate the help and I will keep you guys posted, but keep the suggestions coming!

 

[sam24th]

Ima jump on the bandwagon and also say its probably the alternator going out. Mines was whining on an off until it completely locked up one day. Found out it lost a couple bearings and was whining occasionally. Good luck with your repairs.

 

[Ben824]

Jeeps have horribly inadequate battery cables and they wear out over time. Even if the connection is tight corrosion can make its way down the cable inside the lining in between the strands and cause electrical issues. I would first start with new cable ends at the battery. If there is fraying definitely fix that because it is not helping here. EVERY XJ I have ever jumped off or replaced a dead battery in has had a very tough time staying running. Two theories I have come up with for this is A) the battery is so dead that it is like a vacuum sucking up all the power the alternator is putting out so that it can recharge, B) the computer has had no power in it and its memory has been reset and has no stored data to go off of for start up closed loop running mode at idle so it just dies. But you don't need to worry just sit there for a few minutes with your foot on the gas holding it right around 1000 rpm and it should eventually run on its own. If it does not start to run on its own after a while then you may have something more going on. The whine could be that the alternator is going bad OR the alternator is working double time trying to out juice back into that battery. Seeing as it started fine when you got back home I would start with cleaning up your battery cables and making sure your connections are good and clean and fresh. And the whine of the alternator since it doesn't seem like your battery is bad, then I would bet it might be going bad. Its not hard to get that alternator out so you could pull it and take it to your local parts store and they will have the machine there that can test it for you and let you know if it is bad.

Hope you get the problem sorted out!

 

[SDH281]

Thanks for the help!

 

[01yellowxj]

Steve, I agree with Ben824. My White 99 had something similar happen and I ended up running a new positive cable to the starter, swapped the alt out, and added two extra grounds and never again did I have problems with that XJ.
Good luck brother

 

[highspeed]

You issue really sounds like a bad ground. I would check the ground in the battery or the battery itself can have internal issues. Start with the easy stuff first.

 

[SDH281]

Thanks again for everyone's help! Turns out it was bad cables. Got them swapped out and I am good to go!