Ok, I got back on to the router! Thanks Jlake!
I didn't want to use the bridge method as it will slow the wireless down. I'm going to try and use an IP outside of the main router (AC66U) IP's and the "route" to the secondary router.
Here's my issue. Connected the router through a LAN port directly to my laptop, but can't get in using 192.168.1.1. The yellow light flashes for traffic, but the browser can't find the software.
I've done a 30-30-30 reset and still nothing. Firewall is completely off and not connected to my...