Magic Lights

Greetings,

I have a 2002 Jeep Grand Cherokee Laredo. I went out to the garage this morning and the lights were on. The car hadn't been driven for 4 days and was just parked in the garage. Interesting enough we came back from a months vacation 2 weeks ago and the Jeep battery was dead. Woundn't charge up and was replaced. My belief is that something similar happened with the lights when we were away and killed the battery.

Any ideas where to start looking. I don't have a wiring diagram so that would be helpful as well. Since I am on a limited budget, if it is something costly, can I disable something to fix the problem?

Thanks for your help!