[davepl]

I would run a dedicated heavier gauge wire from the battery (or junction box) back to the pump. Then a relay between it and the pump. I would then use the fusebox "IGN UNFUSED" terminal to trigger the relay. You can hide a kill switch while you're at it if you so choose. This can be small gauge because it's just triggering the relay.

The heavy gauge power wire must have a fuse. A circuit breaker would be the alternative I'd use as you need the pump to get you home, and that's how they did it with headlights, so I'd follow the factory lead there.

I would also highly recommend, at a minimum, a cheap Ford collision interrupt. You can get them on eBay cheap. If you're in a wreck it pops a button up like a breaker so the pump doesn't prepare you for immolation.

As for me, I went one further. I have the crash sensor and I also bought a GM "lift pump" relay kit for a Duramax. It serves two purposes:

1) When the key is first turned on it runs for 10 seconds or so to fill the carb bowl(s) and then turns off so it's not annoying you all the time

2) When it sees an RPM signal it turns on.

3) When it loses an RPM signal it turns off.

That's how the factory wires them, and that's how you should too.