Okay, you've just bought a new stereo / CB Radio / Amp / HAM radio / etc. And you want to wire it in. Where do you get the juice?
To do things the "right" way, you'll need the following:
This same type of trick can be used on the factory head lights, and auxiliary lights.
Run a 10-gauge wire from the battery to a relay under the hood then to your aux. light + terminal. Then use the dash mounted switch to run a very small amount of current to energize the relay (you could even use the ALWAYS HOT or SWITCHED ON circuits we just built to give juice to the switch in the cab). This will result in brighter lights (more juice, less distance) and safer wiring into the dash.
For your headlights, JCWhitney sells a big metal box for $17.95 that has two relays in it. You'll need to do some "fabricating" on your existing head-light connectors (and buy some new ones perhaps), but the same idea applies. Run a big wire from the battery to the headlight relays, then to the headlights. Use the existing harness/switch to just energize the relay. On the stock lights, this takes the usual 10volts to the 13volts your battery puts out.. much brighter lights. Also, it's safer.. less juice running through the dash.
-Tom Mandera, June 1997