Steve, Ensure all bulbs are good(test them), check all fuses and relays (I believe there may be separate fuses for each bulb) locations should be in your manual. Other things that may cause issue with lights are bad grounds, corroded damaged wires,plugs, multi function/ headlight switch defective, if equipped faulty FCM (front Control module), BCM faulty.
Check the attached links,instruction and guides on how to trouble shoot and suggested tips on what to try before replacing parts., Good luck.
I hope this helped you out, if so let me know by pressing the helpful button.
https://www.2carpros.com/questions/dodge-caravan-2001-dodge-caravan-headlights
http://www.automotiveforums.com/t356943-help__weird_headlight_problem_01_caravan_.html
http://dodgeforum.com/forum/dodge-caravan/201079-headlight-problem.html