Engine DC Power switch & Catalina Eletrical Diagrams

[Steve_in_lex]

New owner here...quick question:  

If I understand correctly, the Engine DC Power switch, which is next to the main battery switch, allows power to go (or not go) to the engine's starter motor.  I can't think of a reason to ever shut the Engine DC Power switch off, but there must be one.  Thoughts?

[Stu Jackson]

Steve, the Mark II manual on our website shows that the boats only came with one 1-2-B switch.  Unless the factory added the engine switch, it appears it could have been installed by the PO.  In general, it remains good practice to shut all DC switches off when leaving the boat.

[Steve_in_lex]

Thanks Stu - this confirms that I'm not crazy because I didn't see any reference to the second switch in the manual either.  It's definitely there and looks factory installed.  I'll just turn it off when not in use...there must have been a reason for them to put it in.

[Fred Koehlmann]

Hi Steve,

We have the same Mk II. That is exactly like our main DC power switches under the nav table (only ours are right side up  ).

When we leave the boat during the week, everything gets turned to off (except maybe the DC Panel switch/breaker).

When we arrive at the marina, we turn the 1-2-B-Off switch to a power selection and the DC Panel breaker on, this way we can listen to music, have the lights on, turn the stove on (propane switch).

When we plan to motor out of the marina, we then turn on the DC Engine switch. This switch we then leave on while we are away from the dock (even when on anchor). The reason for this is because one night when our anchor dragged, I tried starting the engine and forgot we had turned on the switch, so now if we are not at dock, that switch stays on. Except... when you want to play with the engine. With this switch off, the boat can be powered up but not the engine.

The windlass switch breaker only ever gets turned on when we plan to lower or raise the anchor, other wise we keep it off.

[Stu Jackson]

Frederick, thanks for noting that.  Does your written manual reflect the two switch installation?  If so, it might be helpful to post that page of the wiring diagram here, and I can link it to the wiki.

[Fred Koehlmann]

Hi Stu,

There is only one (1) 1-2-B-Off switch, just like on most boats. The other "big" red switch is just an ON-OFF switch for the engine/starter. In between are two switches/breakers for the windlass on the bottom and the DC panel on top. I have the PDF of the manual somewhere, but I thought that I actually downloaded it from this site. I'll take a look.

[Stu Jackson]

Thanks, Frederick.

If memory serves, that switch layout in Steve's picture looks very much like the new C355.  Their wiring diagram can be found in their owners manual:  http://www.catalina355.net/owners-manual.html  PDF page 37 of 64.

I'd be interested if it is the same.

[Fred Koehlmann]

Yes, it does look similiar. The only difference is that the bilge is on bank one instead of bank two. (see diagram below). I have the PDF of the owners manual. Would you like me to email it to you, to post on the site?

[Stu Jackson]

Fred, thanks, best to send it to Dave Sanner to post in the wiki, unless you're a wiki expert, I'm not.

[Stu Jackson]

Here's the C355 battery wiring diagram, looks like the OEM C34 Mark II with two switches (1-2-B and I/O)

Please note that this shows a dual house bank arrangement, which is how the boats come from the factory.

This wiring diagram DIFFERS from the C34 Mark II manual on the Tech wiki which only shows ONE switch, the 1-2-B switch.