Does anyone know what would cause the horn and the lights to go off for periods of 1min every 5mins when the car has no alarm.

1998 Honda Accord

If I turn the lights on to low or full beam the flickering of the lights and the horn stops. But as soon as I turn the car completely off the lights and the horn starts up again.

Well maybe it has a factory alarm.. have it checked at the dealer where you purchased it from..