I've not played with the lights on an HJ60 much before. Is it Cdn spec? If so, you have the evil center tap system, which allows you to run 12V lights, and draw evenly off the 24V system. Sounds like something has mucked up in that system...maybe the fusible link off the highside negative pole, which powers the dimmer switch (where all the evil magic occurs). Get yourself a voltmeter, start at the headlight pins, and work back.