Getting ready to put dual optimas in my 90D250 and the battery I'm taking out is an older coach battery from our motorhome thats about to die.I always do a draw test with a test light and wouldn't you know there is a light draw. I pulled every fuse and circuit breaker one at a time and then all taken out and the draw never went away.I called an auto electric shop and they quoted $90 per hour diagnostic. No thanks. Any ideas where to look next?