Battery Parallel Switch

Ocean did some wonky stuff with the primary dc electrical. I totally rewired the battery compartment on my Yr 2000 43' and installed a parallel switch in the process. Prior to that the boat had no battery switch disconnects and had all DC wiring going to buss bars mounted directly on the battery terminals. There is a thread regarding 43' Oceans on this forum and you can see pics of what I did.

With respect to your question, on my boat there was a solenoid in the battery compartment clearly designed to combine the house and start banks but I could never find any reference as to how to actuate it. The one occasion when I killed my start bank and had to parallel them, I had to manually combine the hots at the solenoid. I "believe" the solenoid was tied into the starter circuit somehow but could never actually figure out how to operate it. And the battery mess was so bad I ripped it all out and started from scratch.

Another Ocean owner explained how this worked last summer. To parallel the batteries, you need to hit the start button on both engines at the same time. That's what opens the combiner switch. I never found it in the owners manual, but I did verify that it works.

My boat has wiring that disconnects the starter if the engine is running (I think it's measuring fuel pressure?)

Mine is a 55 with DD's, so I can't help you there. Sorry.

I tested my combiner by starting one engine and having a meter on the other engine's side of the combiner and could see power. I'm not sure how your system is setup, but mine is overly complex. My batteries are 12v and only bridge to make 24 when the start button is pressed. Really more complicated than it needs to be, but too much trouble to change now.

I've only had the boat for a year, and it's taken me most of the last season to really understand it.

I've had an intermittent start issue on the port engine. too intermittent to really troubleshoot and figure out what the bad part is, but I think it's the 12-24 combiner. My mechanic buddy finally saw it at the end of the season, and just pushed the start button a dozen times and it started. Not a true solution, but I'm looking for a spare one of these over the winter.

The other issue I discovered, the "other" battery that makes the 24v doesn't get charged by the battery charger. I had issues starting on launch last year as one of those batteries was low and we couldn't just run the generator to charge and jumper cables were useless. I ended up using a battery booster on the low battery and then started. It took us almost an hour to figure it out. I want to avoid that this year somehow.

I do have a device that looks like that, but I think that's the part causing my intermittent starting issue. I'd like to replace it but can't find a part number. Any advice on the actual part? I'll buy a couple to replace the ones I have and have a spare.