Hi Greg-a merry xmas to you and yours. Of course you are dead right-I tried to keep it as simple as possible for Stackas sake. Dealing with the vagaries of electrical systems when starting from scratch is not easy so hope I did not mislead you Stacka. The arcing and heat with the probes do indicate a major draw as you say. Whatever the problem is it would appear that it has to do with the reconnected wiring from the defunct alarm or a recently added device such as the hardwired GPS.
