Yesterday I finished bolting on my old TRX Slash 4x2 electronics to my new 4x4 TRX Slash rolling chassis. I also added the 2.4Ghz Tx/Rx from Tower Hobbies. I charged a battery, straped it on & turned the radio & ESC on. The ESC lit up & the fan spun but nothing else. Not even steering. The instructions show a on/off button on the Rx, which mind doesn't have. An optional on/off switch and 4battery pack came with the setup. I also got a second Rx for another truck, but the optional on/off switch did not. So how do I get this to work?