Lighting Help

[alf1096]

I have just bought a 70 stepside. The person I bought it from put 47 chevy led's in the bed. During the day the the leds work perfect!!! The lighting problem starts when I pull the knob out for the running lights the whole back end of the truck goes dark. I turn the lights off and I have lights again. I already checked the ground and they are good. I got all the lights to work twice but the minute I turn them off and then back on I have the problem again. Has anyone had a problem like this. Could the switch be bad? If the switch is bad would that keep the front lights from comming on also

Thanks for the help

kody