Trojan Boat Forum

I have an Onan 4.0 mcck I think series J
It stopped running after about 2 hours
I changed the bridge rectifier because it went out twice before so I thought it was suspect
Turned out the 4 month old fuel pump went out
I replaced it but still no luck
It's a long shot but I may have installed the bridge rectifier incorrectly
I cannot understand the wiring diagram
If someone could give me the position of the bridge rectifier positive terminal I could verify the installation
I believe all my wires are in the right place but I may have rotated the rectifier
thx
rr

Give Bob a call at beacon marine. He knows these units well. Also has all the parts

thx Prowlersfish
Bob solved the problem for me
turns out I installed the bridge rectifier incorrectly

still having some problems
I have read that while the generator is running, shore power should (must?) be disconnected
and the switch at the electrical panel set to "generator"

I have an inverter (not an inverter/charger)
The question is, with the generator not running and the shore power disconnected
can the switch be in either position (generator or shore power)?

I get power from the inverter when the switch is in either position but does it make a difference?

Also, does anyone know how long it takes to fry an agm deep cycle battery charging at 16 volts (improperly)?

rr

Not sure how your inverter is wired. But since you get power in any position It sounds like its wired directly to the boat wiring. And it would feed back to the generator if its in the generator position. Same with Shore power.

What charging your battery at 16 volts? Charger, engines or generator? 16 volts is not doing the battery any good for sure.

the 16 volts is coming from the charging circuit of the generator
the inverter is wired directly to the boat
It automatically connects and disconnects
Not 100% sure how that generator/shore power switch is wired

With the shore power cable connected and the generator not running --
switched to generator there is no power to the boat, so I suspect the scenario of running
the generator and shore power at the same time is not possible.

Will the inverter power the boat when switched to generator and generator not running?
I thought so but not sure, I will have to report back.

rr

If your charging at 16 volts than the charging diode is bad per Onan, Beacon aka Bob has one in stock.

charging diode has just been replaced
not sure but I'm thinking if it is defective there is no current not too much
battery has tested bad
I will install a new battery and retest
If problem persists I will test charging current and or resistors r2,r4,r5
and report back
probably a couple of weeks

where did you find that information from Onan, that might be helpful?
thx
rr

A bad battery can cause over charging. replace and recheck. Can you post some photos of your generator? There are some differences. Is the generator original to the boat?

The info came from some calls I made.

Happy New Year to all!
and thanks for all the continued and meaningful support

update:
I installed a new dedicated generator start battery (now isolated)
all is well

rr

Glad the battery took care of it, Happy New Year