ok ive got an 05 supercrew xlt..everything was working until i tried to install a new cd/nav unit, the pioneer avic-z2...ive done radio installs before so i think i did everything right...but first it started out i get everything installed and it works fine but the truck wont start..so i had it checked out and it needed a new fuel pump relay...this is fused to the fuse panel in the passenger kick panel so i had to take it to the dealership to get that replaced...now it starts and runs fine but when i turn on the headlights the engine shuts off and also it wont start again unless u turn the lights off...also the gas gauge isnt working and something is wrong with the airbags and also only the back right speaker works....like i said weird...any ideas??

 

Go back and inspect everything you did to be sure you performed the installation properly. Inspect everything in the area where you worked to be sure you didn't inadvertently screw-up something else. If all else fails, remove the install and see if everything starts working properly again.
GOOD LUCK!

 

i tried removing everything and putting all the factory back in...still same problems

 

I'm gonna say you should let someone else install radio equipment for you in the future.