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I am wiring my truck with all non-stock components (fire sale). I need to know if I can connect a key switch between the positive side and "S" on the starter solenoid without a relay or fuse or should I have both? Also when wiring the fuel pump through "run" on the key-switch, and ignition module, "run" on key switch, do I need relays or fuses between these and the load. I would really love a basic wiring diagram that a rock crawler might use just to get running. Thanks for any advice, suggestions.
I need to know if I can connect a key switch between the positive side and "S" on the starter solenoid without a relay or fuse or should I have both?
Yes, just the switch will work, if it's an official ignition switch(built to handle the load).
If you want something quick and dirty, but still safe, find a large circuit breaker for automotive use, and hook it to the hot wire to the battery that feeds all the electrical. It should be big enough to handle the load, but still be able to open up in case there is a problem. You don't want it to catch fire, and the battery is definitely big enough to turn those small wires red hot.
Also when wiring the fuel pump through "run" on the key-switch, and ignition module, "run" on key switch, do I need relays or fuses between these and the load.
The fuel pump needs a relay. It's just too big a load to run through the ignition switch.
The ignition module and coil can be run through the ignition switch.
You did not say what EFI set up you are using, but, you should probably use a relay for it since it probably draws close to 15 amps. You can use an ATO fuse for 30 amps that feeds the relay from the battery. If it keeps blowing because of the sudden loads, you can use a 2 prong ATO relay instead.
For the starter sol. use a 10 amp ATO fuse between it and the ign. switch. Search here on FTE for "+duraspark +conversion" in the 67-72 forum and you should pull up some useful information.