Ignition breaker?

I will begin some trouble shooting tomorrow but I admit I suck at it. Alright, its a 86 2001 The Ignition breaker will kick out when the engine has been Idling for about 3-5 minutes. after it cools off it starts real good. This problem has gotten progressively worse over the last week. While I'm running there is no problem so it hasn't affected ski time per se. . Other symptoms that might be related are; the volt meter has been registering lower readings progressively even thought the alternator is almost new. . Today I jumped the ballast resistor thinking maybe it may be a factor, including my starting problem when the engine is hot (she starts immediately when cold) , I have electronic ignition so I'm told I don't really need it. I'm not sure how to label a search for this problem yet, plus I won't have time till the weekend but any advice would be greatly appreciated!! .