Cab4you26

Hello all, I have. 1993 cherokee with 250k and have recently noticed a persistent problem. A few months ago I'd be going down the road just fine and my jeep would suddenly jerk and then go right back to driving fine. Very similar to what this guy says in his thread: https://www.cherokeeforum.com/f2/wtf...d-96940/.....I kinda pushed the jerking aside and kept driving it, lately I noticed my jeep would shut off while driving. It didn't matter what speed. It wouldn't big down or anything. There was a sudden loss of rpms for a second then it'd pick right back up, and I'd continue on my way. A few days ago on my way home from work my jeep shut off as I stopped at an intersection. I cycled the key and it fired right back up, drove home, and no problems. That same night I went to move my jeep and I cycle the key and there is no juice whatsoever. No radio, no lights, no turnover, no nothing. This is where I'm at. I put an ignition switch in it and that didn't fix the problem. I'm a little stumped right now, so any advice from you jeep guys to lead me in the right direction would be awesome!

nickxj94

Check the battery terminals for coroded cables, also check all the grounds, and cable to the starter.

MtnHermit

Have to agree, battery terminals and/or grounds.

Klroach92

I would check your grounds, try tapping on the starter a bit, if your not getting any juice at all, check terminals and connections from battery. other issue could be a million things, do you have a ohmmeter?

Jjs2000xj

If it dies like this while driving, I would suspect the connections to the alternator. First step I would take is check the grounds on the alternator as well as the + connection to it. Being the xj is like most (without an overly complicated PCM) it will run without the battery connected correctly but not the alternator which is delivering the amps required for spark

DFlintstone

Not to disagree with anyone above, but a few things. Do you have a ceramic ballast resistor on your inner fender near the air cleaner? If so, it just knocks down voltage to the fuel pump, can be bypassed, and it's not rare that it's connections go bad. It can be bypassed.

Random dieing is something that pesky CPS can do. You only have a resistance test for yours. I don't know the spec, but you might want to look into that. (won't tell you it's good, but might tell you if it's bad)

Then I have this "canned";

Battery gasses have a nasty habit of helping a thin, hard crust form on the bat post's and clamps. They can look pretty good, but that micro-thin layer is a surprisingly good insulator. SHINNY! Lead is what you want. I use a pocket knife, (gently), for the insides of the clamps. For the posts I might use one of those post cleaner wire brushes, but still scrape it with a blade. If you have a condition where you have power, (dash lights ect.), then when you hit it power goes out altogether, that's a common result of a layer of oxidization there. Btw, a half *** connection could be expected to get hot during cranking, or while it's trying. Cleaning those is something to do now and then anyway, so if you are having starting problems, you might want to make sure you have bare lead on lead. Might save you some grief!

Cab4you26

Sorry it's taken so long for me to reply. It's been hard to make progress with all the rain we've been getting. So I had the jeep half taken apart because of the ignition switch. I've buttoned everything up. I checked the voltage on the battery and it showed 6.5 volts. I checked it the next day and it showed 6.4. So I took the good battery out of my corolla and it fired right up. I drove it to advance with the good battery to get the discharged battery tested. They charged it and said it was good. I don't know the extent of their battery testing, but I brought my jeep home and put the corolla battery back in the corolla, and the "good" battery back in the jeep. It fired up fine. I disconnected the battery and my jeep has been running for about 30 minutes without it, so I'd say the alternator is good. However my brother thinks the alternator is still suspect because it might not be putting out enough current. Haven't checked that yet. Also, I checked voltage on the battery with nothing hooked up to it, it showed 12.26 volts, 30ish minutes later and it's showing 12.10 volts. My friend who is an electrician says their is a little bit of leeway with the battery dropping voltage as long as it doesn't drop below 10-11 volts? Opinions on this? I'm a little confused by this as the store said the battery was good, but I wonder if it could still be bad seeing as how it was 6.5v one day and 6.4 the next (although this was while it was hooked up to the jeep, so their could also be something from the jeep drawing power, but I have a feeling the battery is just bad).

On another note, while I know this is a jeep forum, this still kinda relates..
So back to the corolla, I put the good Corolla battery back (12.6v). Hooked the cables up and went to start it. It wouldn't even crank over. I checked the voltage at the cables and it showed 12.6. I checked all fuses and they're good. The dash lights and radio work. My other friend (not the electrician) said even though the battery and cables show 12.6v it could still not start if the cables aren't tight enough. I should also mention that the instrument cluster lights, marker lights, other interior lights flicker while the battery is hooked up now. Idk if that's to tell me my cables aren't tight enough or what? Any thoughts? I just drove my corolla yesterday it's my DD.

DFlintstone

A lead/acid battery that has been resting for a good while, fully charged, with no load whatsoever, (not even a clock), and under no charge, at 78* will be around 12.7 Volts. It's temp sensitive. 12.5-6 @ 50-60* might be normal.

I use to live and breath Toyota's! (still have a pretty cool 72 Celica)

Battery gasses have a nasty habit of helping a thin, hard crust form on the bat post's and clamps. They can look pretty good, but that micro-thin layer is a surprisingly good insulator. SHINNY! Lead is what you want. I use a pocket knife, (gently), for the insides of the clamps. For the posts I might use one of those post cleaner wire brushes, but still scrape it with a blade. If you have a condition where you have power, (dash lights ect.), then when you hit it power goes out altogether, that's a common result of a layer of oxidization there. Btw, a half *** connection could be expected to get hot during cranking, or while it's trying. Cleaning those is something to do now and then anyway, so if you are having starting problems, you might want to make sure you have bare lead on lead. Might save you some grief!

Cab4you26

I cleaned the battery posts and cables with scotchbrite and nothing happened. I popped the clutch in the Toyota to get it running. The light flickering is what gets me. It'll eventually go off. Then if I open the door or something they start flickering again.

Jeep battery is now at 12.08.

MtnHermit

That's a very low voltage for summer time. I replaced my 13 YO battery in my Tundra, it had a no load voltage similar to that number. It would only start the engine if I had just charged the battery. New battery for a month, zero problems.

You can take your battery to a parts store, Sears, Walmart, etc. All will load check it for free, of course they'll want to sell you a new battery. Figure $100 +/-.

DFlintstone

X2^....Something like 11.85 might be 1/2 dead. If it's really been well charged, again after a long rest, it should be over 12.5. A good charge can take a while.

(a "freshly" charged battery will show higher, but that maters not)

Cab4you26

I haven't checked the voltage on the old battery yet so I'm not sure if its dropped any lower. I have a "loaner" interstate battery in it now. I drove it yesterday with the Jon boat on the back. On the way home from the lake the gauge consistently dropped voltage until I lost the radio and the lights dimmed. I couldn't start it up after shutting it off. Do any of you know if these have external voltage regulators or if they're in the alternator? A friend I've been talking to about it said the diode in the alternator could be going bad. That's pretty much where I'm at right now. Haven't checked anything else yet.


Aside from that, I did get the corolla sorted out so there are no more issues with it.

Pelican

Regulator is in the PCM and they rarely fail. Doesn't mean it never happens of course.

A battery showing ~6 volts typically is not just dead, it's likely gone, particularly if it gets this low several times.

Radi

Check your battery voltage with the engine off, then again with the motor idling.
Then with the motor still idling, turn on the high beams, set the heater blower on high and measure the battery again.
The second and third measurements should be higher than the first. Let us know what numbers you get.