This has been covered before but has been lost in the thousands of posts that followed it so here is a new diy.

to keep your fog lights on with your high beams you will need a 1.5" piece of wire (14ga should be fine) and 2 crimp on spade ends.

strip and crimp the wire like this:


now you see the two prongs on the fog light relay that are bigger? #3 and #5.
that's where you will put your wire, like this:


now the fog lights stay on with the high beams and you have a spare relay.

*apparently this only works for 98-01 rams with only one fog light relay.

i put my factory fog lights and the bumper lights on a relay so they all work with the factory fog light switch.
here's my diagram


and here is some useful wiring info -- https://dodgeforum.com/forum/1906003-post41.html

well, i got a little insight into the dual fog lamp relays. read on...