I recently lost spark on port motor the first run after having two 400 watt amps installed. Could this possibly be related? Both amps are connected to the port battery. Both batterys are new but was loosing charge on port battery after a short period of time even before amps were installed. Engines have the blue MSD ingnition boxes. Any insight would be greatly appreciated. I would hate to replace a control box only to fry another one because of the amps or a bad battery. Thanks.

the blue boxes seem to crap out alot,and they are voltage sensative,everybody i know with a blue box has had at least 1 fail.

I lost MSD boxes after batteries were discharged listening to music. I put on the MSD noise reducer and never had a problem. I am far from an expert but I did have this happen. I don't know why but I am suspicious of the high electrical flow from the alternators trying to charge the weakened battery.