best "key on" power source under seat
 

before l do things my way l thought l`d post about this.l`ve added a PLX wideband system and some other items which require a key on power source. l`ve located the respective modules under the drivers seat for a number of reasons and since there`s key on power already there for the relay and ECM it seems a good fit.The question though is where would you draw power from under the seat.l don`t think the PLX or FP guage module have high power requirements looking at the feed wires.Nothing is stated in the destructions either.Any help appreciated:) as always

I would run a line to the fuse box with another inline fuse.

l considered going off the fuel pump circuit also.This wouldn`t be a key on power but that would be fine for this application. l`m always looking for a better way....

Save yourself or the next owner some trouble - go with the fuse box. What I've tried to do when wiring accessories is go off a fuse for something non-essential. If your accessory malfunctions, the fuel pump isn't something you want acting up. Likewise headlights, etc. There's a fuse in there for things like electric mirror adjust, seat heating, cigarette lighter, etc. I'd use that. and fuse it, as Mike suggests.

l`ll probably do that,thanks amigos.With all the extra electronics l`ve added it`s a challange to keep things simple,clean and easy to understand down the road.l try to use OEM wiring and connectors from wrecked cars if possible.