Could be a ground issue, could be an issue with the headlamp switch. Check ALL of your connections before going further.
(Wouldn't be a bad idea to consider doing the relay mod)
Sent from a Jeep.
My 5.2L Build thread
-1989 Jeep Wrangler 2.5L, soon to be 5.2L
-1996 Jeep Grand Cherokar 5.2L, donor and rainy day driver
-2004 Kawasaki KLR650 sunny day driver
"A well regulated Militia, being necessary to the security of a free State, the RIGHT
of the people to keep and bear Arms, SHALL NOT BE INFRINGED