2002 dodge ram 1500 p/u

my best friend is having electrical issues.parking lights wont work.everything else works fine.fuses are ok ...any ideas?

Only the parking lights don't work? Usually there are a few other things on the circuit as well. Do his turn signals work? Did he check the fuse with an ohm meter? I had a car once where the fuse appeared to be in good shape, but it had a small crack in the filiment you couldnt see, i checked it with an ohm meter and found it bad. Are the wiring connections in good shape and the wires themselves intact? Was anything changed or fixed on the truck that could have pulled a wire or connector off, or possibly cut the wire. You won't always blow a fuse in those cases either.

i forgot to add.... If all of that checks out to be ok, check to see if you have power coming into the circuit from the fuse block, sometimes a cracked fuse block won't send power to the right circuits. Then, check to see if you have power coming into the switch and if you have power coming out of the switch to the lights. after that check to see if you have power at the bulb connection. If you have power up until a certain point, then thats most likely your problem. For example, if the switch was bad, you would have 12v coming into the switch from the fuse block, but when you turn the switch on, you will have 0v going out to the lights.

bad switch?

they have checked all the obvious ,but still nothing.

well, if they've checked all they obvious, what did they find out?! What did they check in the whole "checking the obvious". A lot of times it could be something simple like putting a wire on the wrong terminal, or the fuse in the wrong slot in the fuse block. Do voltage checks to see where the power is being lost, or in some cases, you might be getting only 1 or 2 volts to the lights, which would indicate usually a pinched wire somewhere. You can also find a service manual for the 2001 Ram 1500 or the 2003 Ram 1500 (the 02 is going to be one of those builds most likely) here, which might provide a wiring diagram for the circuit you're looking for.