2003 ford ka multiple electrical problems ?

The car is in great condition, flew through the mot after having a petrol pump fitted, having been off the road for approximately 2 years. 1st the dipped beams then went out and no fog lights, then the full beams stopped working, along with the offside rear lights and reverse light, and the heater fan. I had the headlight bulbs changed with no change. Someone says the relays are the fault, someone else says that's unlikely. Can anyone help?