JAL64

I have a 1996 Cherokee Sport 4.0 liter. My issue is intermittent starting. Often when I turn the key I only get a "chunk". Sometimes this is accompanied by a half-hearted attempt to turn over. Eventually it starts. Once running, all is well.

I have noticed that when I turn the key to the "run" position, the battery gauge reads just above the lower red line, I would guess approx 6-8 volts. When the engine is running the gauge reads approx 12V and holds steady. It does change a tad when lights or ac blower are on, to be expected. The battery was replaced about a year ago due to a defective cell. The battery lugs were replaced at the same time. Last week I took it to a shop and was told the problem of not starting was "likely" a defective rebuilt starter (which had been replaced 5 or 6 years ago). New rebuilt starter was installed but I still have the intermittent start issue. (it started fine at the shop and the next time I used the car). The mech told me not to worry about the questionable gauge reading as he had seen similar readings before.

Regardless of what the mech told me I am still questioning the gauge reading low. Is it really somewhat normal for it to read noticeably low when the engine is not running and then jump up to expected level when it is running? Could this be a symptom of other unresolved defect, such as loose wire or alternator / regulator? I would expect a loose wire to cause other issues such as rough running.

Would it be telling me anything significant if the gauge reads "normal" if I disconnect the Jeep battery totally and then jumper from another car? I did have to jumper once to get the Jeep started about a month ago but I did not disconnect the Jeep battery at the time.

moparado

If the cluster gauge is accurate, 12 volts is not enough to charge the battery.
You should first eliminate the alternator as the culprit.

When the gauge reads low with engine running, measure the voltage across the battery terminals and then across the the battery clamps with a hand held voltmeter. Both readings should read somewhere in the ballpark of 14 volts DC. If the clamp reading is higher, then the clamps are suspect.

If the battery voltage measures some 14 volts then i'd suspect the battery, loose wire terminals somewhere or a short circuit draining the battery and pulling the battery voltage low.

In that case you might want to go to a shop and have them place an ammeter in series with the battery with engine/ignition off to see if there's any appreciable current draw which could be draining the battery (overnight).

BlueRidgeMark

Step 1: Get yourself a voltmeter and confirm the voltage.

nujeepguy

never unhook batt while running, alt may go too high, should not, but may

Fred/N0AZZ

Do this first the alt should be reading 13.8v + or
- at the battery if it is working properly, but several things to consider once you have a base line.

jordan96xj

Your symptoms imply that the system is getting proper voltage when running and getting voltage from the alternator, but that battery alone is not providing proper voltage.

The most likely culprits are:

1. Bad connectivity in the battery/starting/charging system, such that the battery is never getting properly charged even when the system is running.

2. Bad battery

Start by cleaning up all connections thoroughly. Take a voltage reading of the battery (without the engine running), then start the vehicle with a jump start (or other means). Then test the battery voltage while the system is running and ensure that the battery is seeing approx 14+ volts. If after letting it receive 14 volts for some time (30 minute drive, or whatever) the battery voltage is not better then when you started (with the engine not running) then you are likely dealing with a battery that just isn't accepting a charge any more.

Here is a video to help with cleaning up connections:

JAL64

Thanks to all who have responded. I have been ill the last several days and being on the computer was not one of my higher priorities. Hopefully in the next few days I will feel like getting dressed and in the garage to check things per your advice. Good food for thought and appreciated. I'll update this thread when I have anything to add. Thanks again to all.

nujeepguy

do they clamp on bare wire cables .i dont trust clamp connectors, not solid..

MWMahoneyJr

Subbed.

JAL64

Thanks to all who have offered advice. I have disconnected battery and metered it: 12.8 Volts. Cleaned lugs and replaced. Car starts fine now but, gauge still reads low with engine off. Apparently nothing to worry about.

LACK

Measure the voltage at the battery with the engine running. Report back with results.

nujeepguy

mine reads low till running. goes to 14 quickly

SilverfoxXJ

Mine is a 96 sportand I had similar issues!
hunting in glovebox and found waranty card for battery? Supriise ! 5 years and one month old1
My guage hovered just above the red for years, and after a few jump starts I thought to check?
put on charge over nite and it always started!