Scout II Wiring Hints

While wiring my own Scouts, I've come across a few interesting discoveries, and my own ideas on how to wire things "right." I'll concentrate mostly on adding new accessories, vs. troubleshooting the "big" problems, or engine wiring, or...

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:

With your parts gathered, the fun begins:
  1. Remove your original + battery cable terminal (unless you already have a bolt-on style in good shape)
  2. Replace the terminal with the new bolt-on style, after putting one or two of the O-ring crimp on connectors on any/all bolts you can. You should be able to get at least 4, more like 6 or 8 on a single connector. You can determine how many you need by reading ahead. Hook the terminal back up LAST
  3. Now, add up your concurrent amperage requirements. Round up to the nearest 30amp increment. This is how many 30amp relays & fuses you'll need (unless you want 30amps of non-switched juice, then forget the relay for that run)
  4. Make a short run of wire from the battery mounted O-connectors to an inline fuse, rated at 30amps. Do this on each run of wire. On the other side of the fuse, run the wire along the driver fender, using wire-ties, and then through the firewall through an existing hole. You can use the stock wiring harness holes, or the holes around the brake pedal rod.
  5. Inside the cab, find a place to mount your new fuse panel(s).
  6. If you need "constant hot" wires for your Headunit clock, or whatever, mark off a few fuse "slots" as "ALWAYS ON". For these fuses, run the hot lead direct from the battery (through the inline fuse) to the fuse panel. Make short "jumpers" to go from the hot lead to each of the "ALWAYS HOT" fuses. NOTE: all of the "ALWAYS HOT" accessories must draw 30amps or less concurrently. If you need more juice, use two hot leads, and divy things up so 30amps or less is concurrently drawn across each hot-lead to the battery.
  7. Use appropriate fuses for each component wired into the ALWAYS HOT fuse panel.
  8. For the "SWITCHED ON" items (which most things will be), like a CB radio or the main power lead for your Headunit, you'll need to use the Relays. Mount the 30amp relays under the dash, running the (fused) hot battery leads to one side of the relay, and the other side of the relay to the fuse panel. If you have accessories that need less than 30amps combined, you can jumper multiple fuse "circuits" together on the HOT side to one 30amp relay. (NOTE: make sure you wire things up to the relays in the "normally opened" configuration).
  9. After the big wiring chores are done, you'll want to use a FEMALE crimp on connector, to an inline fuse of 5amps or less (I have no idea yet) which will then be connected to the extra male tab on the stock fuse panel, above the RADIO fuse. The other end of this wire needs to go the + side of each of the Relay's "electro-magnet" coil (I can't remember the "technical" names at the moment). The - side of the magnet coil goes to ground. (NOTE: there isn't a + or - side.. just make sure one end is "HOT" the other is ground)
  10. Now wire all of your accessories to the appropriate fuse block, using female crimp on connectors. One block will only be "HOT" when the key switch is in the RUN or ACC position, the other will provide juice all the time. BE CAREFUL WHAT YOU ATTACH TO THE ALWAYS HOT. It wouldn't be fun to leave your CB radio, or head unit powered up all the time, and find a dead battery when you go to start your Scout the second morning of a long camping trip...
    1. 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