Looks like a faulty ground hookup... +1 on sbarron's comment about something seriously wrong...
1 thing I will say in your defence though, the wiring on our trucks really sucks in regards to durability. Just by wiggling some harness around you could have caused a serious short-circuit or just plain broke a few wires' sheath making current jump from one wire to another triggering all sorts of goofy behaviour like you are describing.
You need to figure this out real quick before you deal more damage to the electrical system. It could cost you big $$$ if you blow the IPDM or PCM*. The '04 don't have a separate TCM, it is integrated with the PCM so your tranny not shifting is already a very very bad sign of things going on right now.
Hope you can figure it out soon before more harm is done.
I would start by disconnecting the light bar all together. If that resolves the problem, then there 2 possibilities. The wiring you have done for the light was improperly set-up; or you have triggered a wire breakage like I described above in the harness you tapped into.
Also, these light bars draw a lot of current and they should be set on their own separate circuit. The headlight or fog light relays can't handle the additional load they carry. There are free available relay slots in the IPDM for that very specific purpose.
Hope this helps
