Found the problem, ordered the part, kept vehicle in safe and secure location until part was delivered. Made repair and tested. Had my vehicle back before hurricane Nicole hit. If you can't figure out why your new battery keeps draining on your 1999 Ford Expedition with 4 WD, it may be the GEM module. Upon researching how to make the repair, I am very happy I didn't have to do it. Great job, great service, great at explaining everything. Thank you. I have a dependable vehicle thanks to you.