My headlight on my 1990 Arctic Cat Jag continually blows headlight bulbs. I've replaced and verified the correct bulb as well as replaced the voltage regulator but it still blows bulbs. I'm thinking next steps are replace lighting coil or main wire harness. Any ideas or someone who's been through this? Thanks.

are you getting greasy finger prints on the bulbs when your putting it in???

the first thing that comes to mind is voltage regulator, im not sure exactly how it works but even if the coil was putting out to much wouldnt the regulator still regulat it?
i doubt the coils bad, but have you tried reistance through it to see if its within specs, and mesuring voltage at your bulb?

Agree, the coil is likely not the problem. I do have the service manual and can check the resistance and voltage values vs, spec.