ov10mech
Member
Hello,
I have been battling a frustrating 12v problem on my boat for some time. 1995 Sea Ray Sundancer 33
I just had the port side alternator completely rebuilt and they fully tested it. It’s a Mando 55A alternator.
I also have 3 DELCO Voyager Deep Cycle Batteries brand new (95 AH Each) .Two are wired in parallel on the port side where all the accessories draw off and for starting port side. The third battery serves the starboard side engine only. I have taken off all the batt connections , cleaned and re tightened everything down. I put a 135A load tester on each battery to make sure they were ok. Everything tested ok under 10 sec load.
Everything charges fine at the dock with on board charger. I always check the voltage as soon as I unplug the shore power . Port and starboard side show a little over 13v (engines not running and nothing drawing)
Now, if I start the port engine and monitor voltage it’s steadily a bit over 14 which I believe should be telling me the charging on that side is ok.. at idle anyway.
Here is where it gets interesting. When I start increasing RPMs my voltage actually drops on the port dash gauge. I recorded a short video of this here:
http://www.youtube.com/watch?v=dzaqDyjZ3q4
To rule out the gauge being bad I also put a multi meter on the back of the gauge and it is indeed dropping in the 12s when RPMs go up. BUT, If I put a meter on one of the port batteries while revving it does not fluctuate at all.
So my symptoms are usually dead batteries on the port side after parking for dinner for 2-3 hours . The only thing running is the fridge. I would think on 2 fully charged batteries this should be no problem. When I go to start the boat I sometimes have to jump the port side using the emergency switch that takes juice from the starboard battery. My theory is the more I use the boat, the more the port side drains since I effectively don't charge above idle and leaves me little capacity when docked away from my slip.
So at this point I don't know if its possible I may have hooked something up wrong when i replaced my rebuilt alternator or if I should be looking elsewhere?
Sorry for the long post.. Just wanted to include as much info as possible. If you have any other tests I can run I am all ears.
I have been battling a frustrating 12v problem on my boat for some time. 1995 Sea Ray Sundancer 33
I just had the port side alternator completely rebuilt and they fully tested it. It’s a Mando 55A alternator.
I also have 3 DELCO Voyager Deep Cycle Batteries brand new (95 AH Each) .Two are wired in parallel on the port side where all the accessories draw off and for starting port side. The third battery serves the starboard side engine only. I have taken off all the batt connections , cleaned and re tightened everything down. I put a 135A load tester on each battery to make sure they were ok. Everything tested ok under 10 sec load.
Everything charges fine at the dock with on board charger. I always check the voltage as soon as I unplug the shore power . Port and starboard side show a little over 13v (engines not running and nothing drawing)
Now, if I start the port engine and monitor voltage it’s steadily a bit over 14 which I believe should be telling me the charging on that side is ok.. at idle anyway.
Here is where it gets interesting. When I start increasing RPMs my voltage actually drops on the port dash gauge. I recorded a short video of this here:
http://www.youtube.com/watch?v=dzaqDyjZ3q4
To rule out the gauge being bad I also put a multi meter on the back of the gauge and it is indeed dropping in the 12s when RPMs go up. BUT, If I put a meter on one of the port batteries while revving it does not fluctuate at all.
So my symptoms are usually dead batteries on the port side after parking for dinner for 2-3 hours . The only thing running is the fridge. I would think on 2 fully charged batteries this should be no problem. When I go to start the boat I sometimes have to jump the port side using the emergency switch that takes juice from the starboard battery. My theory is the more I use the boat, the more the port side drains since I effectively don't charge above idle and leaves me little capacity when docked away from my slip.
So at this point I don't know if its possible I may have hooked something up wrong when i replaced my rebuilt alternator or if I should be looking elsewhere?
Sorry for the long post.. Just wanted to include as much info as possible. If you have any other tests I can run I am all ears.