540 vette

I have a 2000 Grand Cherokee Laredo with the 4.0.

My wife drove the truck to work today. Started fine in the driveway, she stopped to get coffee started fine again. She parked it in the train station and it sat there for 10 hours and when she went to start it when she got off the train it just clicked. I jumped the truck and it started right up. I drove it home with no issues with the lights on and the radio on. I parked it and went to start it it just clicked. I checked the battery voltage and it was 12.44 volts that is after driving it for about 10 miles from the train station. Still just clicked. Jumped it again and it started right up and ran fine I could hear the alternator hum and checked the voltage and it was 13.78 volts. I removed the positive cable while the truck was running and it didn't stall as if the alternator was bad. Put the cable back on and let it run for about 15 minutes. I shut it off and the truck just clicked when I went to start it.

Battery is 8 months old, connectors at the battery are new and clean. I couldn't check the connections at the starter and the ground.

I'm leaning towards a bad battery, maybe a bad cell. Not enough amperage to start the truck.

Dave68

Your 13.78 reading and the drive home without incident, indicates the alternator is probably good.

Do you have an automatic battery charger that can charge with 10 amps? If not, you should get one. I have a Craftsman that was $40 on sale. If you do have one, run it at 10 amps and observe the needle. It should start out at very low charge and slowly move toward 100%. If it continually shows no charge or is acting strange, it could be the battery. I would then have the battery load-tested.

By the way, I believe when it comes to modern-era vehicles with lots of electronics, it is not advisable to remove either battery cable while the engine is running.

540 vette

I actually changed out the battery this morning with another and the truck started right up. Pu the old battery back in and just clicked.

I know it's not good to remove the cable.

TA

I've had two Jeep WJs and I'm not sure why, but they were both very tough on batteries. My last one (04, 4.0) went through four batteries in the 9 years I owned it.

MVR 155

Just had this same issue with my H2 battery (which was only about 3.5 years old). The truck would start just fine but if you had the doors open for any length of time (if I was loading/unloading things from the vehicle), went in and out of the vehicle multiple times in the evening (automatic lights come on when you unlock the truck) it would be slow to crank. It got to the point where it was hit or miss and I had to start jumping it or throwing the charger on in the mornings I drove it. I checked voltage and it was good, was getting good charge from the alternator too. I pulled the battery and brought it to Autozone as it was still under a prorated warranty. The rep there said it tested just fine.... I explained my symptoms along with the tests/checks I had performed and he said the battery was fine. I offered to re-install the battery in the vehicle and bring it back so I could show him as it was bad enough if you left the hazards on or the lights on for less than 10 minutes the truck would not start (just click). After some back and forth he agreed to warranty the battery..... good as new again!!!!

If your battery is under warranty and they say it tests fine make sure you let the rep know what you have done to isolate the problem.

540 vette

Ther problem was the battery, I brought it back to Wal mart and they gave me a new one.

540 vette

The problem was the battery, I brought it back to Wal mart and they gave me a new one.