Electrical Problem

[David VAsichko]

Purchased a 2000 Amberjack in Jan of this year. It has twin 5.7 mercruisers. Have been working thru a few minor problems; leak in lower unit seal, module in distributor went bad on port, etc., but have 2 electrical problems to resolve. Currently have put about 75 hrs on engines and now have 550 total on each.

(1) the starter battery and emergency battery drain whenever after about 2 weeks of nonuse. This is after all breakers and mains are turned off. I am dry stacking this boat and unable to hook to shore power.
(2) This is the worst problem. Went offshore a couple of weekends ago. Ran engines at about 3400 RPM for 2 hours. Trolled for several hours and when returning, lost starboard. Blown breaker in galley. Each time trying to restart, would blow breaker, even just turning the switch to on position and not trying to crank. Jiggled all the wires on engine; still blowing breaker. Ran for about 1 hr on port, tried the starboard again. Fired right up ! Have put another 7 hrs on both engines; no problems. Mechanic couldn't find anything and, of course, says to give him a call next time it happens.

 

[eddiezuskin]

Can you take a look at wiring diagram and tell what does or can turn on when you put the ignition switch in the on position as that is when it is blowing? Can you disconnect one by one some of those items to run down the culprit? I could be totally off base but it could be a wire that is shorting intermittantly. I would turn key to on and if it does not trip the breaker start going around wiggling wires trying to make it trip the breaker. Cure it or kill it mission. LOL
Eddie

 

[David VAsichko]

Could a loose connection cause the breaker to blow? Seems like it would be a dead short...ie...like a bare wire touching metal. But I am unable to locate anything like that.