Alternator excitation
- Thread starter 907Juice
- Start date
Yeah that is what I’m thinking. That is item #2 right? It has 4 prongs and it is still on the 1st prong. Or maybe 4th??? It is on one of the ends...
Yeah I know we want 14v. That is what started this whole journey. I think I have a few good places to start. I only mention the lower volts because that would confirm everything functions normally and it is the alternator that is bad (still)
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The joy of boats again surface. 
Things rattle and role in a boat. They work their way loose, just to torment the boat owner. Sometimes even we are the cause catching a wire as we turn to crawl out of a confined space.
What was one of the first suggestions? Follow the wires....
So happy you found the problem Now you can sigh a sigh of satisfaction, sip a beer
, and sin no more.... Until the next time.
Things rattle and role in a boat. They work their way loose, just to torment the boat owner. Sometimes even we are the cause catching a wire as we turn to crawl out of a confined space.
What was one of the first suggestions? Follow the wires....
So happy you found the problem Now you can sigh a sigh of satisfaction, sip a beer
, and sin no more.... Until the next time.
OKOK, old problem separate solution. Whenever I start the motor, I now (almost) always check to see that I’m getting 14v. Well, that happens about half of the time. It is resolved with some cursing and unplugging and plugging the panel a few times. Then the motor bears down and it jumps from 12.5 to 14. Is there any electrical magic that happens through the circuitry between the 61 plug and the panel? Looking at the diagram and following the wires, it looks like it just goes through a series of harness jackets to the panel. Could I just run a wire straight from the alternator to the house battery.
It is common to run a wire from the alternator output to the house bank. A little less common is to fuse that wire appropriate to the wire size(at battery end), even more uncommon to put an Alternator Service disconnect in clear view of the alternator.
Each of these less common items will make your boat safer for it and those who work on it.
Les
Each of these less common items will make your boat safer for it and those who work on it.
Les
Well I’m most of the way there... already ACR’d up and I’ll be sure to fuse the alternator wire. So you can add me to the even less common column.
907Juice... It is not the ACR (automatic charge relay) that Les is talking about. It is an ASD (Alternator Service Disconnect) switch. You use it to disconnect the battery (which you have directly connected to the positive side of the battery. When the engine is off the Alternator Positive connection is Hot. Tap the ground wire or a screwdriver to the alternator and your getting spark city.. The disconnect switch is the safety feature that keeps you hair from turning white as you work around the engine.
Oh I gotcha. I got my acronyms blurred. Not sure about an ASD but I have a negative switch to totally kill all power to the dc system. Is that close enough?
Yeah I’ve zapped myself a couple times and it is more a zinger than painful. Doesn’t take many times before you learn to turn the power completely off.