check the automatic circuit breaker first(long shot). It is a small rectangle cube with two posts and the power wires connected to them. This normally will only kick out if there is a surge but could be intermittently contacting. I doubt this is the culprit but they do make some noise when they activate.
I am more inclined to believe something is not right in the wiring of the headlight system. You should be able to actually feel a relay when it activates. I would remove the panel while it's hooked up and feel each relay as the noise comes up. This will identify the relay causing the noise. Follow all attached wires to their ends, either as power leads or to the limit switches mounted on the headlight frame and the radiator support. Also, check to be sure your limit switches are getting good contacr in the open or closed position and check each wire from the limit switches back to the relay board. I would lean towards a defective relay if you cannot find a wiring problem. At this point(or before), if a relay is producing the noise, swap places with it and another relay which is not making the noise. If the same relay moved to a different spot makes the noise, buy a replacement. If the realy switched into the spot makes the noise and the other previous noisemaker quits, go back to square one on the wiring attached to that relay.
[This message has been edited by backfire (edited 07-24-2001).]