Last week I was at the lake, battery was down. I carry a spare with me, I unhooked the old battery and hooked up the new one. Started the engine .. good so far .. then with the engine running ( so I could charge up the old battery ) swapped leads. to the old battery. Well I can see thats not a good thing. I believe that I saved the rectifier but my new tachometer is smoked. Should have stayed on the new battery.
