Aux Fuse Box Relay Trigger Wire

[Dyn Blin]

Presuming I get the back-up lamps circuits trouble-shot, and my retrofit wiring loom done to remedy the trailer wiring rat's nest removal, I hope to get back to the original "easy" project of installing RocketMan's voltmeter conversion, and swap my dash cluster lights for LED's this weekend.

Concurrent with the the voltmeter installation, I'll install a accessory fuse box for some radio/aux lighting/electronics, and run the voltmeter to one of the terminals.  I'll use a fuse box unit that I've used on my motorcycles- I prefer the model since it has an integrated relay and a unique solution to swap a terminal between switched or constant hot on-the-fly.

I thought I saw a previous thread where Gary had done the same, but can't locate it now- maybe I saw it on FT...

I have a lazy question related to the trigger wire- I need a switched circuit wire proximate to the battery
 & easy to reach to tap & energize the relay- I'd be obliged for recommendations?  

[NotEnoughTrucks]

That's a pretty tough one! Only thing I can think of is the accessory power applied to the windshield wiper motor. Black with a light green strip.

[Gary Lewis]

I suspect that was on FTE, here: https://www.ford-trucks.com/forums/1313748-power-distribution-box-schematic.html

As for what to use to trigger the relay, you could use the white/light-blue hash wire that goes to the ignition module, as shown on Page 18 in the 1981 EVTM here: http://www.garysgaragemahal.com/start-ignition--carb-circuits.html

[Dyn Blin]

Just what I was looking for.

Thank you gentlemen.