I would like to say hello to everyone on here!, I have been searching all over trying to find out a solution to my problem, I have a 1998 standard cab long box silverado. My dome light, the lights that you turn on manually in the dome light, my cargo lights or my 3rd brake light, none of them work. i have checked all the fuses (unless im missing one.) kinda stumped on this one, bulbs are good. everything else works awesome on the truck. help would be much appreciated!

 

So the overhead dome lights, third break light, and the white cargo lights - the white lights that shine into the box, are INOP?

It's curious that your stop lamp doesn't work, but the other two on the back of the truck work fine. Have you pulled the lens off of the third light to check the bulbs and power/ground at the connectors? Remember that the third break light does't work as a running light, it is ONLY on when the break pedal is depressed. The white cargo lights only work when the switch is flipped, and a door is opened. I believe the cargo lights are operated with the interior dome lights.

Also welcome to the forum!

 

The cargo light will only work while the dome light is also on (something I soon plan to fix on my truck). I'm not sure if these lights share a common ground, but it may be the case if they all stopped working.

I'll check some wiring diagrams later today.