I would like to know which wire I can hardwire my radar detector to so that it'll shut off when the trucks turned off. Which wire is it coming out of the fuse box? I've found a few posts about this but wasn't exactly sure which wire to use. Thanks!

 

The easy thing would be to install an add-a-fuse in the slot for the radio, if you want the circuit by the fuse panel.

 

i just hooked one up today.. my detector had 2 wires hot and ground i grounded the white and tucked the red one in next to the fuse for the wipers. therefor it will only come on when i turn the key... didnt want to hook up to radio bc i have amps and such running w it.

 

I always wire mine into the EEC PWR relay output so it's only on when the engine is running. But any key-on circuit will work. These pics show how to add terminals to the fuse block so all your add-ons will be easy to service:

 

I've tapped the radio turn on lead on my last 3 F-150's for my Escort 8500 and have never had a problem.