12v power for escort radar detector

I have mounted my Escort Passport 8500 x-50 on the std (manual) rear-view mirror with a Blendmount mounting adapter. (Not that I drive too fast very often...) - Ran a smart-cord around the a-pillar down to the fuse box area on driver's side. Tried adding a circuit using a Littelfuse add-a-circuit with mini-fuses and can't get power to the detector. I added circuit into the fuse marked "Power Outlet" (15 amp), but the littlefuse is only a 10 amp unit. The power outlet still works (both the one in front and the one in rear) but no power to the detector. I plugged the detector into the front power outlet with the original cord and it still works, so there's something wacky about my wiring or the add-a-circuit. Also noticed the power outlet fuse is 15 amp, so tried the front seat heater outlet, marked as 10 amp. Still didn't work.

Any suggestions on how or where I can tap into 12v switched wire (easily), or what I'm doing wrong with my add-a-circuit.

 

I want to use the Escort Smartcord so I can mute the alarm easily. Thank you for the suggestion but that wasn't the answer I was looking for.

 

I don't recall seeing any labeled IG, but will look more closely when I get back into it this weekend. Sounds like exactly what I need. Thanks!