Which ground do I start with?

[gogo14910]

Interior light is on when door open, when I close it, the light goes out but the cargo light comes on. Cargo light stays on no matter where the switch is positioned. When I open the door the cargo light goes out and interior light goes on. They have this battle, one comes on when the other is off. Where do I put a ground? Isn’t that always the answer? Thank you all.

 

[Jgonick]

Interior light

Interior light? courtesy (floor by ash tray) or dome or both?

no matter where the switch is positioned

What switch? The headlight pull switch when turned or a separate stand alone cargo switch?

They share the same grounds- the white wire goes to ground at door jamb switches when doors are opened and/or the pull head light switch when turned all the way to the left.

 

[Vbb199]

Check your fuses, this sounds familiar.....

 

[gogo14910]

Interior light? courtesy (floor by ash tray) or dome or both?

It’s the courtesy/dome play opposites with the cargo. All 3 work but that cargo light is giving me fits. The cargo light comes on when doors close and turns off when doors open.

What switch? The headlight pull switch when turned or a separate stand alone cargo switch?

The stand alone cargo switch. Headlight pull doesnt effect it.

They share the same grounds- the white wire goes to ground at door jamb switches when doors are opened and/or the pull head light switch when turned all the way to the left.

Where does this white wire originate? The door jamb switch, or the headlight pull? Maybe it needs to be sanded and secured better?

 

[Jgonick]

If your courtesy & dome light are working- then your grounds are okay. (at least up to the dome light) The cargo light uses the same white wire (ground) as the dome light. It connects to the white wires that ground at both door jamb switches & headlight pull switch (when turned)

The cargo light also uses the same Orange wire (feeds power) as the dome light.

So your problem is probably located somewhere from where the cargo light connects to the dome light wires to the cargo light itself. The connection (if I remember correctly) is at the base of the driver side C post.

The switch should stop the power (orange wire) going to the cargo light. So since it is not working, the switch is bad and/or the cargo light is getting power from somewhere else it should not.

Also - somehow the cargo light is making ground somewhere it should not.

This all based on your truck having the original wiring. No modifications.

edited to try to make it easier to understand.

 

[Jgonick]

You can try removing the horn/dome fuse Or unplug the orange wire that is plugged in the front of the fuse box that runs to the dome light.
See attachment
That should kill the power to the dome and cargo light.

 

[Grit dog]

Seems random until it actually happens, but check the cargo lamp bulb.
Possible wrong bulb in the cargo light. I chased a similar issue for hours only to find out the bulb in the cargo lamp was the wrong kind and was playing the same shenanigans on me.
Someone put a 2 post bulb in a single post socket or vice versa.

 

[75gmck25]

IIRC, the cargo lamp housing is insulated from the truck with small spacers to stop it from being grounded. It always has power on the orange wire.

If the interior lights are on, and the cargo light switch is on, then for correct operation the cargo light has a ground through the door switch or turning the headlight switch. It sounds like yours is finding a new ground path.

 

[gogo14910]

If your courtesy & dome light are working- then your grounds are okay. (at least up to the dome light) The cargo light uses the same white wire (ground) as the dome light. It connects to the white wires that ground at both door jamb switches & headlight pull switch (when turned)

The cargo light also uses the same Orange wire (feeds power) as the dome light.

So your problem is probably located somewhere from where the cargo light connects to the dome light wires to the cargo light itself. The connection (if I remember correctly) is at the base of the driver side C post.

The switch should stop the power (orange wire) going to the cargo light. So since it is not working, the switch is bad and/or the cargo light is getting power from somewhere else it should not.

Also - somehow the cargo light is making ground somewhere it should not.

This all based on your truck having the original wiring. No modifications.

edited to try to make it easier to understand.

I had to unlike this so I could like it again. All original wires and this makes sense. I’ll look into it and let you all know. Thanks to everyone for suggestions. I’ll have a few options with these! Thank you.

 

[Jgonick]

but check the cargo lamp bulb.
Possible wrong bulb in the cargo light.

Definitely do this first.. @Grit dog is right. always always check bulbs first with weird light problems.

Also Maybe this diagram will help.