Electrical Issues!!!HELP

[52MercRR]

My son has a '72 C10 SWB. The dash, brake and tail lights quit working. I printed off the electrical diagrams from this site(Thanks). I have no power on the fuse block upper right fuse. This looks to come from the connector for the dash assembly(gray wire). What I can't tell is where this power originates from. I can't find anything that tells me how circuits are switched. The drawings show multiple wires from the light switch, but not how they are controlled through the switch, i.e. N.O., N.C., which wire connects to which at each detent of the switch when activated. Can anyone shed some light on this issue? Any thoughts are appreciated. Thanks.

[Longhorn Man]

You checked the fuse? I think the one you say has no power is the dash light fuse. It gets fed off the tail light fuse.
If you check the electrical forum, in the FAQ thread, you'll find a photo of a fuse box that has been labeled.
Assuming I am right, once you install a new fuse, it'll probably blow. You'll need to take note of exactly when it blows to help figure out whats actually wrong.

[VetteVet]

See this thread and it should be able to answer all your questions.

http://67-72chevytrucks.com/vboard/s...d.php?t=416018

[52MercRR]

Looked at continuity check for light switch posted by Fixit P, my switch ohms different. Headed to Autozone to try new switch(already replaced twice). I will ohm the new one in the store with Fluke multimeter before heading home. Thanks for the information sharing. I'll post response later.

[52MercRR]

Finally found short on brown wire going to front side marker lights. Thanks for all the input.