Why does the battery on my Jeep Grand Cherokee keep running down?

when they tested the alt did they check the dioides if not then it could be feeding back and killing the batt good luck

You can do a few things, take apart as many connections as you can and clean them or make sure they are clean, under the hood and the alarm , make sure everything connects back together good, if you can find a completely super dark place like in a garage with all the lights off, run the engine and look for sparks around under the hood and below, don't fill the garage with exaust or you can fall asleep and not wake up, keep your fingers out of the way for any moving parts, no loose cloths or jewlery, also you can go to autozone and have an electrical check and computer checked for free, make sure someone follows you incase you need help,

Is the battery losing charge while not attached to the vehicle? Remove all battery cables and run tests several hours apart. You might have a battery that's too sulfated to keep a charge. Do a battery acid percentage test.

You can pull specific fuses to check certain circuits in the cable harness and find the circuit that's draining the battery, too. I'd start with the large current pullers like starters and air conditioners first. You might have a ground short in the circuit.

You will have check with an ammeter what current is being used while engine not running , all lights and equipment off etc.. Sounds like battery is charging while you are running but something is using current when not running.. might be a fault in a switch or component.. might need an electrician to check each circuit individually,,,

pull a battery cable and see if you attach it slowly if there is a huge spark, or check it with a battery charger, the current meter on it will tell you if something is pulling current which should only be the radio or hood light, if you have a amp meter that would be good too,

there could be a shorted diode in the alternator and most times you need to remove it to have it checked correctly,

You have a short. In other words something on the vehicle is drawing down the battery. Check all electrical components start at fuse box. Use to be the number one culprit was the dome light.

The battery on my Cherokee just DIED. It was properly maintained and I had no problems with "shortcircuits". They certainly dont last for ever,mine was only 4years old ! Try disconnecting yours, charge it up using a good mains charger and see if it holds a charge. Otherwise it`s off to your local Unipart agent and cough up about £120 !!!!!!! (but not if you know someone ! )

1

How old is the battery ?

They dont last forever - after 3 years its time to change.

Its a jeep....simple as that! Get a Landrover 110 or 90, basic, no frills, no elecktrickery problems and will still be running after youve buried half a dozen jeeps :-)

Mike.

1st off, without proper diagnostics you cannot get a proper repair...with that being said...

2nd, it sounds like you have a short in the wiring or starter, take it to a trusted and certified technician and let them do the proper diagnostics and proper repair.

good luck and hope this helps