1998 jeep grand cherokee

I believe you have to check amp draw, I don't believe checking volts will tell you anything. With key off, there is always a little draw, the question is how much draw, that's where the amps come in to play. If I'm wrong, my bad.

do you have any ideas where it could be

If too much amp draw, check for lites left on anywhere? Best time to check is in the dark, interior--under the hood, where ever. another thing, while watching the amp draw, pull replace fuses one at a time, when you pull the fuse on the problem circuit, then the amp draw returns to normal. Then you check everything on that fuse circuit, unplug the components, one at a time. Those are the basics. Make sure battery has a full charge, battery connections all good. Check your charging system.

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