Hello. I have a 3 way circuit correctly wired with a 2486s keypad and a 2476d switch. The load is on the 2486 keypad and that unit works perfectly. I have setup the corresponding 3 way scene in ISY and added both units as controllers. HOWEVER, the 2476d switch will only turn the lights off. Once the lights are off it no longer has any LED's and is totally unresponsive until you turn the lights back on from the 2476 keypad.... ANY HELP IS GREATLY APPRECIATED!!!

The devices are not wired correctly. Insteon devices require unswitched 120V AC. When a device goes blank as you describe it is not being powered by unswitched 120V AC.

 

EDIT: likely the switch is being powered from Load side of the KeypadLinc. When the KeypadLinc load is turned Off power is removed from the switch and its LEDs goes blank.

 

Insteon switches are NOT like a standard 3-way switch. The traveler wires to the switch have to be retasked to provide unswitched 120V AC to the switch.

 

If you cannot figure it out suggest posting on the Smarthome forum. There are a number of users who are present and retired electricians who may be able to guide you through the process of changing the wiring between the KeypadLinc and switch location.