[Robert Cart]

Thanks, Tony. The photo you sent is what I have. This means it os intentional for the tensioner to be on the loaded side of the crankshaft. That means it is only making the belt tight enough most of the time. However, sometimes, especially with a rapid disengage of a high output alternator, the load can drop fast enough to cause slack on the unloaded side which can whip and reduce belt life. However, I am happy to just assume all is well with this design especially considering the zillions of them put is service. Cheers!

[Robert Cart]

I am still battling with a dual voltage system and have not decided where I land. My latest thought is this. What about using a 24V alternator and starter motor with but keep the 12V panel and starter solenoid? I already must provide low current 12v loads for NMEA2000 and etc. It is then easy to power the panel with that system. This means I can have a 24V start and house batteries and this greatly simplifies charging and redundancy, etc. The 12 and 24V grounds are common so should be no problems there. I serve the 12V loads with a 24V to 12V DCDC converter and in a pinch, I could get home by pulling off a 12V battery to drive the 12V loads if the converter failed. This is all around a nice solution and means I don’t have to replace panels, circuit boards and senders. The solenoid switch on a 24V starter motor might even be able to be rewired for 12V. Alternatively, I use the 12V one off the existing starter. What’s the catch?

[Robert Cart]

That bracket is beautiful with a capital B! I want one. Is is a J180 4″ size? How do i send you a direct note?

[Robert Cart]

Hi Tony, is this something that you can help with? Also, I’m wondering is if a J180 cradle mount could simply use the same bracket but attached to the outside rather than the inside? The outside measurement of the existing bracket is 3.5″. I would need to add 1/2″ to make it 4″ for the J180 and also fill the middle 2″ so the tabs on the alternator won’t break when the bolt is torqued. The 1/2″ extra could be added where needed to align the belt. Sounds dodgey.

The better alternative is of course a new J80 bracket that fits into the old hole pattern used for the 2″ delco mount.

[Robert Cart]

That is very helpful, Tony. Thank you. I have attached a few photos that I hope will help you see what I need.

[Robert Cart]

Corey Schmidt wrote:

You should not have to replace the tach due to voltage IMO… can you verify 100% what device is driving the tach gauge? Alternator? Mag Pickup? Generator drive?

Corey, I am away from the boat and can’t check now. I assume the alternator drives it. It is a very simple engine. No ECM or turbo or anything complicated so I’d be surprised if its not driven by the alternator.

My list is getting slightly shorter because the starter includes the solenoid/mag switch.

I am still wondering about the engine side of things. Does the circuit board use the water pressure sender for the gauge and the alarm or is there a separate alarm switch? What about for the oil pressure? Do you have a wiring diagram for the engine itself a 1994 6B5.9M?

I’m a data hound and am also interested in adding additional sensors like transmission oil pressure and raw water flow rate and maybe even exhaust gas temp. Can you guys help with the parts I need?

[Robert Cart]

Thanks, Tony. A second alternator would offer a hot backup. Also, if one of these 100 amp units failed, it would be easier to find a replacement in some far away port even if not 100 amps it would be something.

I only hesitate now because I”m almost overwhelmed with all the work on deck now. The added cost and complexity of the belting and bracket and wiring isn’t enticing. I’d probably also have to rework the cover on the front of the engine to protect the passageway there. Not easy. I’ll keep it in mind as a future upgrade. Thanks again!

[Robert Cart]

Tony and Corey, thank you so much. To switch to 24V, I now understand that I need to swap out the following:

1) alternator
2) starter
3) mag switch for starter
4) panel circuit board
5) lights on panel (alarms and in gauges)
6) fuel solenoid
7) water temp sender
8) oil pressure sender

Anything else? What about the tach? Are you sure I need a new one???

[Robert Cart]

Thank you, Tony. Your advice would be spot on if it weren’t for some crazy requirements I have. I’m on the bleeding edge and am doing quite a few things common only to the most modern boats. For one thing, I’m upgrading the house battery bank to LiFePO4 batteries. I have already pulled and rewired most of the boat for 24V with a distributed two wire bus. I’ve yanked out the generator and I’m not putting one back. I’ll run AC loads off a 3kW inverter. I have water maker, electric winches and windlass, refrigeration, etc. This all leads to needing 200 amps from the alternator at 24V. A 160A 12v alternator and a 300w DC converter wouldn’t make a dent in the demands for this 62′ boat.

On your specific comments, I found a wiring diagram for the B series panel on your site and elsewhere. I don’t have the diagram for how the harness connects to parts on the engine. What I have shows the grey wire from the tach to be connected to either W12 for 12V or W24 for 24V. Since it has those two voltage options, it suggests the panel may be wired for either 12 or 24V? I’m assuming the grey wire is power from the battery via the alternator connection and is energized once the ignition is switched on. I guessed that W24 connection is the midpoint of a simple voltage divider so as to deliver 12V to the panel.

I’ve found this to be a common approach for both dual voltage products. I now know a lot about buying 24V pumps, motors, lights, fans, etc. They often are not clear about whether a product may be purchased in one of two voltages or whether it is dual voltage. The latter was luckily true with my autopilot and fridge compressors.

A new 24V starter cost $124 new so I won’t sweat that or the labor to replace it. A new new mag switch and fuel shutoff solenoid may not be necessary if the panel voltage remains at 12V? As I only want a single panel, $300 would be unpleasant, but not the end of the world.

Questions:
1) Do you know if the voltage source for the panel is delivered via the grey wire from the alternator? Ity appears the purple wire serves as the power supply wire within the panel, but I cannot tell how this is powered.

2) Do you have a diagram showing how the harness connects to the engine components?

Thanks in advance!

[Author]

Replies