Question question about cascading a router on a switch connected to a modem/router.

[Autobot2000]

Try to make a long story short. I bought a wireless home security cam. But where i want to set it up was getting a weak signal. I remembered i have an old router laying around and thought if i could use it to cascade my wifi signal closer to my cam. But here is where it gets tricky or least to explain. I have a modem/router (main) which goes out to a switch which i have my tvs and other wired devices connected to. So instead of making more holes in my house i thought to use one of the cables that runs to one of my tvs, connect that end to my 2nd router's wan port and split that to use the wifi on that 2nd router while also connecting one of the wan ports back into my TV so i could still watch tv but also have the 2nd router be used for it wifi. Only prob is once i turn on the tv cable box the wifi gets i guess cut off/disconnected and i guess that wired connection takes over. What am i doing wrong and what do i need to do so i can use the 2nd router's wifi and wired connection at the same time.

its goes, modem/router (main) to switch to 2nd router, split to tv cable box and trying to use wifi as the same time.

 

[jsmithepa]

Configure 2nd router as Access Point, the gist of it is, don't use the WAN port, hook everything to the LAN ports, I assume you have 4, No DHCP here. BAM! done.

 

[Autobot2000]

Opps error made in my explanation. 2nd router everything is hooked up on the LAN ports not the WAN.