I did a couple of corrections.
I recommend look at this diagram and follow the wires to the things they connect to.
http://67-72chevytrucks.com/vboard/s...27#post9186727
If you have questions, I suggest post them in the electrical section and you'll probably get more answers. Mention the year and type of truck you have, and what type of instrument cluster, gauge type or warning light type, or aftermarket. Pictures of what you're dealing with help.
http://67-72chevytrucks.com/vboard/f...splay.php?f=64