I am a new member and have had my WK Grand Cherokee Limited petrol for seven months. On day three my battery was flat after sitting for 48 hrs. So back to the dealer. They said radio software update required but not available. They added the diesel battery and swapped out the radio to keep me going. Three weeks later at 2am same again. Totally dead. Back to dealer again. Checked and found nothing. After three more trips back to the dealer they claim it was the Electronic Rust Unit they fitted that was draining the battery. Disconnected as they claimed it was faulty. New unit fitted under Warranty by authorized fitter this time.(They were shocked when they saw the unit the dealer BUTCHERED to fit.). Anyway after another trip away 48hrs again this time we were unable to jump start either. So off on a truck to the dealer. They have had it two days and called this morning to inform me the battery was fine and they want it another day to try and find a problem. How many times do I need to take it to the dealer before they fix it??????
Never mind about the rust unit. Apparently not that now. Have now been informed it is the keyless start sensor that is draining power. Great mechanics here at the dealership. Should have stayed with the commodore. At least it only went to dealer for services. The jeep got serviced while in getting this crap sorted. These guys must be idiots here as the keyless sensor will always draw power when the key is in range. So they hook it up to computer and approach vehicle. Wow. The sensor woke up. Surprise. Surprise. Anyway. Went in to get another jeep as a loan vehicle but the two they have are out due vehicles not being repaired in time..
Electrical drain issues can be a bear unless a code gets set. When faced with one I put an ammeter on the battery (normal quiecent drain is under 50 ma. To drain in 48 hours would take over 200 ma). DIsconnect the alternator (shorted diode is a possibility) and if still there then start pulling fuses and relays until the drain goes away. Next troubleshoot that circuit.
If that is unsuccessful then I generally look for a bad ground keeping the battery from charging properly. Is a lot more but that is where I'd start.
Thanks for the info. Will keep it in mind. Still at dealership for them to rectify. Only seven months old and has been an issue from day three. Battery and radio replaced on first visit. Software update on third visit. Rust unit blamed about the sixth visit and this time the keyless start sensor. I wonder what it will be next.