Thanx Rick, yours sounds like the same problem. I changed a few bulbs yesterday but no difference. The buzzing noise is coming from somewhere behind the diesel fill point, and the tone changes with the movement of the dip switch. It made me think that there was a relay on its way out. The lights do not flicker, they come on for 3 seconds, and then out for 4 or 5 seconds. Also when coming on and going off its like something is turning a dimmer switch. Thanks again Rick, electric faults are the worse thin out.