Ok I have a 2006 f150 and I just installed an air/fuel gauge. I hooked the power up to fuse #18 which was labeled run start feed overhead powerpoint and heated seat. Since I did that my battery has died twice so i guess that draws power even if the key isnt turned on. Can anyone tell me where i can tap into a wire that only draws power when the key is switched to on it also has to be 10 amp fuse.

 

Buy a test light, open the fuse box and go to town. There are probably a few unused positions that you can easily find. Test light costs less than $5 in most cases; a worthwhile investment.

 

Another thought. Find a wire that is only on when the key is on. Use that wire to power the coil of a relay. Run a new wire from the battery into NO contacts on the relay. Fuse your new wire at 10A. Just a thought. Personally I am too lazy to try and see in the fuse panel (too awkward). If it were me I would look for the wire that turns the radio on when the key is on.

 

I was thinking of using the radio wire I know exactly where it is since I installed my own audio system. Now that wont interfere with the wideband in any way would it?

 

It shouldn't. All you are doing is using the power as your switched source

 

Ok thanks im going to try that tomorrow.