dash idiot light ???'s

[Billwill]

So much for the days of simple alt or batt cable problems. Lol
I have a scan tool for codes. Later on today I'll pull codes. What if there arent any ??

If there are no codes for the Battery Temp Sensor then it means that is not your problem. You can fit your voltmeter to your interior cigar/power outlet to monitor the battery voltage while driving....if the battery light comes on you may see a sudden drop in voltage at that time!

 

[88dually]

Will that mean its the alt ??

 

[uss2defiant]

Will that mean its the alt ??

Let's just start with the codes and go from there. :gr_grin:

 

[the_dealer]

I had the same issue, but I was also getting noise thru the speakers shortly after the light came on. Then it got to where it would die and have to be jumped off. The only code I got was battery voltage being too low or high. I went thru every connection trying to track it down. I had the alt. and battery checked multiple times. They said I needed a new battery twice, said the battery was good twice and the alt. passed every time. I was going over everything one night and had the hood open with it running. Between the hood and cowl I thought I saw a faint spark. I started looking behind the alt. and noticed it was arcing internally. It was very intermittent, and I'm lucky I was able to catch it. Replaced the alt. and it's been good since. Get a cigar outlet voltmeter (can be had off Amazon or any auto parts store for under $10). When the light comes on, watch to see what the voltage does. If u have access to another battery that will fit, try that as well

 

[88dually]

I'll try that this weekend.

 

[88dually]

Wifes 10 minutes from home an all hell breaks loose. Batt lite on for 30 min. Air bag light dinged, soon after that, a loud clunk under floor near feet. All instrument lights started flashing. Speedo went to 0 . No power while pressing accel, all lights go off, a few min later all lights started flashing again. Got home, i turned car around in driveway an it died with instrument panel lights flashing. Havent been outside to check it. Severe t-storms an flood watch. So i'll have to wait til morning. Oh i forgot, the bcm hasnt been working for a while now, bout 3 months. All this might be from sensor under batt ??

 

[ltd02]

Not sure what you mean by the BCM hasn't been working in 3 months. Did you ever get to check for codes? Mine would do this as I was driving down the highway when I had corrosion on my (-) battery terminal connection. Lights blinking / shutting off, Speedo bottoming out, instrument panel going nuts. I'd imagine it could happen if your alt was going. Mine just kind of died when my alt went. These things are real finicky when it comes to electricity. See if you have any codes now and keep us posted. Alternators are pretty cheap and easy to swap so I hate just throwing parts at a vehicle but might be worth a shot. Still need clarification on the BCM. If that isn't working you've got all kinds of things happening (or not happening may be more accurate).

 

[88dually]

Bcm is body control module.
Havent done codes yet. Was waiting for some kind of problem to come up. The light goes on for her coming an going to work when i'm not there to be able to check it. When she gets home, everythings running an charging normal.

 

[ltd02]

Yes but what do you mean it hasn't been working in 3 months asthe BCM controls all those things that are flaking out and then some. So when you say it hasn't worked in 3 months I'm lost and that's probably all your problems right there.

 

[88dually]

Int lights, door locks, radio, keyless entry (remote clicker), none of these work. Had it checked out an was told bcm was bad.

 

[ltd02]

That'll do all the flaky stuff your wife reported. May or may not be related to the battery light but a flaky power supply to the BCM will cause a real light show and gauge dance. May have gotten a brief surge of life today for some reason. Fix it and your battery light issue may go as well. I'm leaning toward alternator for the battery light but like I said these things are real fussy about their electrical connections. When my gauges flickered due to the battery corrosion issue I'd hear the chime and see a variety of dash warning lights blink or stay on. Usually the ABS and Airbag lights. Don't recall just a battery light at that time.

 

[88dually]

This only started a few weeks ago with the batt light. The dash lights is a first.

 

[ltd02]

All the flashing lights and speedo stuff would definitely be the BCM telling you it's not happy. Gotta fix that thing. I think the headlights and wipers go through it too. I'm pretty sure of that one. I hope Billwill sees this and provides some advice. Always get good electrical info from Billwill.

Maybe the battery light is related???

 

[88dually]

Thx for the info

 

[88dually]

Can i put in a new neg cable to inside of fender and disconnect old cable ??

 

[Billwill]

Can i put in a new neg cable to inside of fender and disconnect old cable ??

Yes, make sure it is a nice thick cable with good lugs on each end and check the cable grounding the engine to the chassis is clean and tight both ends.

We are still waiting for some codes...might point to something....also need a voltmeter inside the cigar lighter/power point to see if any funny things happen to the voltage while you are driving!

The BCM definitely controls all the cluster lights so it is worth getting the BCM seen to....may also be a grounding problem on the BCM.

I would have the Alternator tested or replaced and maybe fit a new OEM thick cable that goes from the alternator to the positive side of the battery...must be OEM because this cable has a built in "fusable link" to prevent further damage or even a fire. You could temporarily replace this cable with a normal thick cable but this must only be a temoporarly fix to rule out the proper cable.

You can check where all of the grounding cables are located in the wiring section of the KJ Service Manual for your year KJ which you can download here......worth checking that all ground points are clean, rust free and tight!

Index of /manuals/Jeep/KJ

 

[88dually]

Any idea where i'd get a thick oem pos cable with fusible links in it ?? Auto parts store or dealer ?

 

[88dually]

......

 

[88dually]

So do the fusable links act like a 160 amp mega fuse, if so....can i just put in a mega fuse ??

 

[ltd02]

I'd probably try a visit to the junkyard. Otherwise it is part of the battery harness and pricy. I'd stick with the OEM unless you try as Billwill suggested and try a temporary bypass.

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