Welcome to TBN & the forum bronco2. Simple answer - your system is not charging. The reasons are just a few. Look in your owner's manual and see what it says. Most likely - a problem with the alternator or with the battery. Check that the ground wire off the battery is in good shape and where it connects to the frame is not corroded. Take the battery to a "battery store" and have it checked. Around here - I would suggest Les Schwab.