Re: WK2 grand Cherokee limited battery issues
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.
Notary Sojac Y'all
One of these is a diesel: