have a 93 d150,with a dome light/cargolight problem,they dont work.fuse is good. the time delay relay was missing as was the lightt and key buzzer,which all play a part in the dome light working.replaced the relay and buzzer relay, now still not working but with the buzzer hooked up when you push the cargo light switch the buzzer goes off.
i cant figure this out im still trying. has anyone had any problems like this ?? also map light on dash and underhood light work which are on the same circut!! just puzzled any help or insite appericiated,thank you.

 

Have you checked the bulbs? There is a wire connector up in the fixture area that may have come unplugged. The wiring on mine runs along the drivers door, if yours is the same the wiring may have become damaged as you can step on it every time you get in the truck. Good luck.

 

i have power at all light sockets,centerpin that touches bulb,new bulbs.
each light socket has 2 wires on it so i know it is a ground problem,just dont know how the ground is made. thanks

 

My cargo and dome light use a double pin bulb and have their own ground wire. If you have single center pin bulbs and no ground wire the ground is made from the brass case of the bulb to the side of the socket and then to the truck body and then to the battery. Are the sockets corroded? Are the sockets tight to the sides of the bulbs? The ground from the battery to the truck body may be bad. You will need to use a meter to check the continuity between the side of the socket and the truck body and then the body to the battery ground. Running a new ground wire to the sockets is an option.

 

finaly got my dome light working was rotted ground in harness near were the seat belt wire splits off . ran all new wires through the cab roof.
now my cargo light still not working[did not work before]
weird thing,the buzzer relay was missing so i put one in when i push cargo light button the dam buzzer goes off???
my factory owners book say dome light is #1004 but it is not 1004 iis a 2 pin bulb the socket is for a one pin bulb another reason why it did not work.
must have been a misprint in the book??
any help with cargo light is appericiated thankyou

 

The cargo light should share the same ground as the dome light. I would start there and trace wires just as you did for the dome light. The older my truck gets the more ground problems I chase. Electrical problems usually just come down to basic wire tracing.