if the regulator is bad the alternator could be overchargeing the batterys which would shorten the batterys life
I had one that had ring and pinion wear causing the problem could be the axle u-joints or wheel bearing assembly. With typical milage for your year you should be ready for either.
Maybe your starter.
It is usually when the ingine of the jeep isn't working properly. Or it could be that somthing else in the jeep isn't working right. You might should take it into a shop to get it looked at. Just in case
being a super duty i assume this is a diesel engine. diesel trucks have 2 batteries. did you check both batteries. then check all fuses if it is a diesel engine there will be 2 batteries .did you check both batteries
Fireworks Batteries
yes watch batteries are different from regular batteries because watch batteries are much smaller and hold less electrical charge. they would not work in anything else other than a watch.
Try an engine heater or an oil heater. These are both inexpensive.
Have other tests run to see if anything else could be causing the rash.
Check the starter relay. Also try to start it in Neutral. Let me know!
Problem in the emission system - have vehicle scanned to determine problem
Like just about everything else, batteries will eventually fail whether used or not. They definitely have a life span.
Could be ALL your bulbs but more likely to be the flasher relay.