Trojan Boat Forum

All,
Having trouble finding any "solenoid" that "connects the two starting batteries together" for "emergency power". Have the twin CAT 3208TA on a 12 meter Trojan Motor Yacht. Also, it says in the wiring diagram that the batts are automatically connected when you are starting. Can anyone verify this and give me some help finding the "solenoid"?

Yes it is automatic when cranking . Check with Beacon marine on the Part ,

Mine is actually in the battery box. Looks factory.

P-Dogg wrote: ↑Fri Jan 22, 2021 4:37 pm Mine is actually in the battery box. Looks factory.

After you posted , I reread the OP . I was thinking he was looking for a part . OPPs . Mine is located in a black box labeled battery sentry right next to the batteries . while We have F boats the location will be near the batteries regardless

The automatic part uses diodes and the crank feed from start switches to activate the solenoid

I am going to try and have my wife hit the emergency power button while I sit in the engine room and listen for a click.

I have ALMOST convinced myself that this feature is not present on our 12 meter motor yacht. The port engine fired right up. The starboard engine would not. It would not even with "emergency power" button depressed. Come to find out my 8D batt on the starboard side was bad. If the batts were truly "tied together" during starting, I would have thought both engines would have had the same response (either good battery would be strong enough to start engines or bad battery would have pulled down voltage enough that neither engine would start)? I am still investigating, and I will post more.

The Automatic part will not work if the battery on the engine is to low to active the solenoid/relay . The switch should be a 2 way toggle per my info . Each way uses a different battery to activate the solenoid , that way it will work if one is dead .

Your owners manual should have the diagram and info . If you don't have one Beacon can get you fixed up with one .

Solenoid will be in this box

Another pic

Prowlersfish you are a genius. All the labels had been taken off my box, but your picture helped me find it. Now I will see if it is working. Thank you so much for the info.

You will find this helpful I believe I had to flip a coin on witch thread to post it on . And please read how it works when one battery is too low . Any question please ask as I am not always that clear when explaining things .

viewtopic.php?f=1&t=12446

Even more info viewtopic.php?f=1&t=11180&p=104964&hili ... rt#p104964 and Beacon has the the parts if needed

Interesting! My solenoid is not in a box -- it is on a plywood board right in front of the batteries. Here is an old photo from before we bought the boat. The solenoid is to the right of the battery switch on the rusty bracket.
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WayWeGo wrote: ↑Fri Feb 05, 2021 11:21 am Interesting! My solenoid is not in a box -- it is on a plywood board right in front of the batteries. Here is an old photo from before we bought the boat. The solenoid is to the right of the battery switch on the rusty bracket.
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I would up grade that solenoid , ground is a poor set up .

Beacon , offer replacement boxes

prowlersfish wrote: ↑Sat Feb 06, 2021 10:21 am I would up grade that solenoid , ground is a poor set up .

It has already been cleaned up partially, but there will be some more done when I replace all the wires to the batteries and add some terminal blocks and fuses.

While the original wiring is mostly intact, the wiring for added devices is pretty bad on even the better additions!