02 KJ Electrical Weirdness...

So, I just got the fuel pump replaced in my Renegade, (-$490), there was an issue when he tried to start it up again after he replaced it so he had to run a new ground to bypass the sentry key module (something I've posted about having issues with several times over the years, code NO SKIM BUS). Since then the Jeep has been very sluggish when starting, like it had a dead or dying battery (I figured that's what it was since it was quite old). Took it to Advance, they tested it, turned out the battery was bad. Bought a new battery (-$120), made no difference. Still sluggish starting up, had to try starting it twice before it actually caught. It runs fine and drives fine, no issues once it's running.

Had a couple come to take it out for a test drive last night (it's for sale at this point because it's too expensive to own two cars) and OF COURSE, as soon as they rev it up, it throws out something completely new: flickering lights, odometer shutting on and off, etc.

Today I went out, started her up, revved it a bit, lights flickered a little but nothing like yesterday. Turned it off, and wouldn't turn back on. Now it's so dead even the remote can't get the doors locked.

Long story short, I'm thinking alternator, which is a fairly easy swap I can do myself. My questions are a) do you think it is the alternator and b) if it is, how do I know which specific alternator to buy? I'm shooting for an OEM but there are several different versions (136 amp, etc.) Is it possible something got screwed up when my mechanic put the new ground in? It was fine before he touched it! He's always been good and fair, and people speak very highly of him so I'm hoping it's not his fault, but who knows?

Thoughts?

swapping out a alternator is truly only about a 5 minute job.

Did you check the battery after the car died?
It could be the alternator and it could be the wiring from the alternator to the battery.

KJs Gal You need to get the testing done . Battery charged up & load tested., then once running see what voltage is going into battery etc. Scan for codes again.
Generally if the something is up with the ALT the light should be on...
Many battery shops like the one that replaced yours can help with further test/diagnostics...even a hydrometer on each battery cell to see state of charge etc.
Was the jeep parked for a long time without charging it? Possible electrical drain down happening?

Anyways if u need a new ALt...re-manned alts are all over the place on price scale, $ 115 to $ 400+
Many have core charges as well.
I wonder if my 136 amp ALt ever went what I would replace it with....hmmm..
I might even consider a local shop to rebuild the OEM one/bench test it...$? 200 ?

Make sure the battery connections are clean and tight, the negative lead going to chassis is clean and tight and the grounding strap grounding the engine to the chassis is clean and tight both ends.

Then with a fully charged battery put a voltmeter across the battery terminals.
With engine OFF it should read about 12.5 volts.

When turning over it should not drop below about 10 volts.

When engine is running it should read about 13.5 to 14.5 volts or else the alternator is not charging.

The red Battery light should light up on your cluster if the alternator is not charging...does this Battery LED work? All the cluster lights should come on briefly when ignition is turned ON or you can test the lamps by holding in the Odometer Trip Reset Button while turning on the ignition...all cluster LEDS should light up and gauges move about.

Where did the guy put in a new ground after the fuel pump replacement? I do not see how you can bypass the SKIM with a new ground unless he jumped out the ASD relay....maybe this is causing current drain when the Jeep is standing.

So we are now thinking it is NOT the alternator, because it seems to run fine after we jumped it and it ran for a while, implying the alternator is charging the battery just fine. There are no dashboard lights on other than the ones that always turn on briefly when it starts (including the battery light), nothing unusual besides those flickering lights the other night (which it did not do today). I already checked the battery terminals and wiring, they are tight and wiggling them around does not affect anything. Advance said the rest of the system checked out minus the old battery, but there was a 16 amp draw when they tested it which he thought unusual.

My mechanic mentioned something about the ground being on the bottom of the circuit board--i.e. "If you turn it over you'll see an extra wire." This is what the Jeep dealership told him to do when he explained it was no longer accepting the chipped key, I guess.

Either way, right now it is back in the shop until he either knows what it is so I can tell a potential buyer, or until he can fix it without charging me an arm and a leg.

If nothing else it has made me love the Civic 10x more...=P

I know gas is expensive and many have a small car (not that I fit into them or want to drive one) The Kj still offers safe roomy & reliable transportation needs.
If I would have a chip key problem, I think I would have taken it to the dealer in the first place.
Soldering in a ground..ah..well..dont know what to say about that other than proper diagnostics and repair count for something in the long run.
I hope you can find a fix KJzGal that works and solves the problem.
Electrical stuff without the proper scanners are a nightmare on any vehicle.

So your mechanic knows how to hot-wire a KJ even if it has the SKIM module fitted...and your dealer knows this too?

I doubt the Jeep will start with a non-chipped key but there may be a problem in the ASD relay area whereby the PCM does recognise the chipped key and energizes the ASD relay but then the PCM does not get the confirmation back that the ASD relay has in fact energized due to a wiring problem. I had this problem on my CRD due to a wiring problem.

So if you want to sell the Jeep with a working SKIS anti-theft system you need to remove the extra wire and do some further diagnosis...you will probably find that pin 30 is shorted out to pin 87 on the ASD relay socket....that overides ASD relay problems but you still need the correct chipped key in the ignition to start the Jeep up.

Got the Jeep back last week, he says it needs a new computer but doesn't see an issue with it other than that. I recorded a video of its startups that I will be posting soon so you guys can see. It almost seems like maybe it's not getting enough gas right away, because it's not had to be jumped after sitting for days.

I have a buyer ready for it once it's fixed (or at least, the problem is known), so this is driving me crazy! I can use the chipped key as normal, I haven't tried an unchipped key yet. He said all he did was unplug whatever wire/ground that had to do with the SKIM for 24 hours and then plug it back in so it would work. I haven't had any recurrence of the flickering odometer issue, but the map lights do still flicker a bit while driving. Ugh!

I doubt that there is anything wrong with the PCM...if you do replace it you would need to re-programm the SKIM data into it.

Have you changed the alternator yet....I have seen a similar post to yours somewhere on the Jeep forums where flickering lights were caused by a bad alternator.....could also be a bad serpentine belt/tensioner.

The map lights (dome lights) are powered by the BCM which is on the reverse side of your inside fuse panel...maybe re-plug the connectors on the BCM!

Any other codes showing up?

So, tonight, tried to start her up four or five times, wouldn't go. Run inside to get my camera to videotape it, go back out, and she starts up just fine -.- Tried scanning for codes with my OBDII reader, didn't find anything, however the malfunction indicator lamp does flash on and off when the key is in the on position BUT the Jeep is not running. I have a new serpentine belt and spark plugs to go in it this week, and the alternator seems to be working normally since the new battery hasn't been dying and it tested okay at Advance Auto.

Is it possible my mechanic screwed something up when putting in that fuel pump? Leak or air in the lines, etc.? It does it regardless of whether it has a full tank of gas or not. It's just really starting to tick me off!

Here's one video of it acting up: https://www.facebook.com/photo.php?v=10202551016280541&l=2682256320799770523