Need help: I have a 2001 sport. Here is what’s happening. About 1 months after getting the truck used last year I was driving along and all of the sudden a warning light in red pops on "Check Gauges" and the VOLT meter was pinned all the way to the full positive side of the gauge. I said to myself wow.. what the hell! truck was running fine.. So i was at a light and i shut it off and it started back up fine, warning gone and away I went.. 4 months later same thing happened.. It only happened about 3 times in the last 12 months and i simply shut it off to fix the warning..

Yesterday I ran the truck up a snow mountain for fun.. I drive away and all of the sudden the 'Check Gauges" light comes on and the volt gauge is pegged all the way to max volts. So as i have done before I shut it off to correct.. HOWEVER, it wont restart, no power whatsoever.. not even flasher power. completely dead.. for 5 minutes I’m sitting at the entrance to a parkway here on Long Island with no power at all... So i look at the tachometer and its sitting at about 300rpm.. I just glanced at it.. my next thing was to turn on and off the headlights for whatever reason to try and jolt something.. as i was doing this I watched the tachometer go down about 50rpm each time I turned the headlights on and off.. when the tach read zero I turned the key and the truck started right up like no problem.. LOL

I proceeded to Best buy to buy something. I came out, opened my door with manual key, unlocked the passenger door for my son with the power lock. I put the key in to start and DEAD no power nothing.. I hit the power lock again and this time dead?? Im saying WTF! No reading on tach.. pulling headlight lever on off nothing.. I pop hood and play around with batter wires.. etc.. more wires tapping.. Then the truck starts..

I got it home and parked it.. Im using my convertible now! What could this be?? I hate to start replacing wires for no reason..

No fuses blown, battery terminals are clean and tight though covered in oil and dirt by the starter..

I found this write up on trouble spots with these trucks.. could the gauge cluster harness be doing a complete NO power situation? Take a look at these issues..
http://www.fourwheeler.com/buyersguides/129_0606_1984_2001_jeep_cherokee_xj/troubles.html

Please help.. should I change the battery cables with a whole new setup?

 

This was a really big post so I skimmed.. What I suggest is put a trickle charge on the battery and if you can somehow, take it to auto zone. Ask for the ignition check. Its free and checks the alternator which is what it sounds like

 

Thanks! What is a trickle charge and how do you do that? and whats does it do?

 

It can't be the battery discharging because it starts right up after I mess with it once dead..

 

I wonder if its a corroded gauge cluster connector.. But how would that cause the car to be 100% dead then all of the sudden start with full charge? That has to be some sort of battery cable or part of the system where power is compltely cut off right? I mean the clock does not even work.. then it will start if I keep messing with ingition or lights.. I wonder if its the batter harness??

 

Check all of you connections really well. I would clean them up at the starter and make sure the terminals are crimped on the cables tight. Also check you ground cables. I bad ground will do this too. Pull it off and clean up both the terminal and the place where it mounts. Take an ohm reading on the cables and see if you have a high resistance. Also start going around and look for voltage drops from you battery back.

 

Hi and Thanks!, I took it to Advanceautoparts this AM. Its started right up in my driveway no problem. I got to the store and shut it off. The guy came out with battery tester said it was reading 12.75 volts and that was high? I think he was high.. He told me to crank it over to test starter and alternator with some other huge device he hooked on it. I turned the key and DEAD.. Nada Nothing.. Whene the car was shut down at the store it had 12.75 volts in the battery. I turn the key and it had 6.5 volts and dead.. I tried screwing with all wires again and bought alternator and starter degreaser and cleaner and cleaned up all the terminals.. Worked great.. No crank.. Asked store for jump box he gave it to me and said we assume no responisbiity for what might happen. I put it on and a first crank nothing (Just a dead key turn no crank) and it drained 1/2 the battery charger. I hooked it on again and let it sit. Its started up..

I drove it 1 mile then as I am driving the voltage guage pegs at 19 volts and check gauge light comes on.. I google electrical service shops in my area and drove the truck to this guy.. I can't be bothered with this kind of issue.. I think it's the harness.. I dont think its a battery drain due to it starting up the last time this happened.. Anyway, I got to the sho, volt meter pegged at 19 volts.. Mechanic shuts it off and it wont start..

I tell him the PCM is in the computer.. He says, OH! Shouldn't he know that? Who's right? Is it in the alternator or computer? He says 90 bucks he will tell me whats wrong and he might even be able to fix it for that price..
All I wan't to know is what it is and I will rip the car to peices and fix it myself. It's worth it to me to pay 90 bucks then cleaning this and that and removing this and that and wasting untold hours with possibly no results. I will fix it..

I think hes full of it anyway.. Im going to get some wild bill.. or some crap.. I DO NOT trust mechanics.. He could tell me ANYTHING at this point.. I will part the truck out and buy a brand new 5.7HEMI jeep next week.. I fix this for fun but now it's getting annoying.. This is so strange even the electrical guy at the shop thought it was weird to see an overvolt situation..

Alternator??
ECU with built in PCM
Turn Signal Sticks
Bad Wiring Harness as per TSB
Burnt or corroded wires anywhere in the miles of it in the car!

I guess Im gonna PAY PAY PAY!!

 

This really smells of a bad ground issue. Ask any ASE technician how they would handle this and most "should" tell you that ground verification/freshening would come first with these symptoms.

Here is more. Yes, there are other possibilities, but unless you want to chase your tail, FRESHEN YOUR GROUNDS!. It's free and it needs to be ruled out before moving on.

Grounds can be the root cause of many electrical gremlins. Refreshing grounds is NEVER a bad idea!

You can't just check or look at these grounds. You must remove, scrape, clean until shiny the cable/wire ends and whatever they bolt to. The one on the back corner of the head, and where it attaches to the firewall. Scrape the paint from the firewall. Best to replace that woven cable with a #4 or #2 gauge cable. You can attach the one end to the intake manifold if you would like.

Next go over to the engine dipstick tube stud. Remove the nut and clean the wire ends and scrape the block until shiny at the stud. Reattach tightly.

If you are so inclined, add at least a #6 cable from the negative terminal of your battery to one of the bolts on your radiator support. Scrape the paint off first.

 

You are so right! I just got lazy.. I was going to rip everything apart including the Under Dash TSP stating wiring harness issues with gauge malfunction. Chrysler has a specfic fix and sequence for fixing this and its involved.

I realize I should have cleaned everything, all cables etc.. I know how to get that done and scrape clean etc.. My problem is no garage and 3 feet of fing snow! LOL.. I do not want to freeze my *** off under 180,000 miles of grease with no lift and ice sheets in teh driverway with no garage. If this was good weather here in NY for sure i would have done everything you said.. I wont pay this guy more then 90 bucks.. He says for 1 hour its 90 BUT if it takes me longer to find the issue I will call you. WTF! I must be stupid.. I can only hope he does the right thing.

My Direcectionals also stick on both directions from time to time.. I took apart the directional lever and cleaned it out internally ( WHAT A BIAAATCH TO PUT BACK TOGETHER) that did not help either.. Somehtings wrong here..

What gets me is the volts pegging at 19 volts.. I see no one else on here with that issue.. Battery is good according the guy at the store?

Your exactly right tj.. It's just too cold here and Im not set up for crawling under a truck in 30 degree weather with melting and refreezing snow all over the place..

 

I understand the weather inconvenience.

But you now know what needs to be done before moving onto more complex possibilities.

Good luck and be sure to check back and let us know the exact cause.

 

battery bad try the one from the convertable see if it fixes it then but new battery

 

Thanks Guys! I hope this electical guy does not pull some bull.. I asked him to tell me ONLY whats wrong with it.. I can fix it myself..

 

Well.. Electrical Repair shops.. Guy charged me 2 hours Labor.. He is replacing the battery cable says its corroded. He said he located a ground short under the dash and that teh wiring harness if fine. The ground short should fix the gauge going nuts and the flashers sticking..

It would have teken me 8 hours to figure that out and that would have been if I got lucky.. Somehow, I think this guy might spend a 1/2 hour total or 1 hour tops.. However, he garantees it for life.. We will see.. I hate blowing cash but when it comes to electrical short I don't have untold hours to find it..