Is there something that would cause the cargo light and the reverse lights both not to work?

 

Most likely it's a pinched wire or a fuse... There is 2 fuse panels in a Dakota - one under the hood, and the other is inside the driver's side of the dash. I'd recommend buying a cheap multimeter from radio shack or some other electronics company - should cost less than $10. You can use the ohm meter to check the status of the fuses quickly while they're still in the fuse panel. If the fuses are still good, then you can progress to the relays, wires, or bulbs.

 

Repaired a chunked wire for the taillights. Backup lights now work after replacing the fuse. Are the cargo lights on the same curcuit?

 

Do you mean the light by the 3rd brake light that lights up the bed? I know the dome light can be disabled by putting the dash light dimmer all the way down/dark

 

It was all the way down. Forgot to check that after repairing the wire. Thanks

 

glad i could help