I have a 2006 44 DB with an Onan...

[Proud_Warrior]

I have a 2006 44 DB with an Onan 9kw genset.  Yesterday after starting the genset while at anchor I noticed I am only getting 62  VAC (vice 120) supplying line 1 and the normal120VAC supplying line 2 in my AC electrical system. I cycled all cb's and solenoids with no change. When I got back to my slip shore power works normally feeding both lines 1 and 2 with 120VAC. So the issue is limited to the genset power source. I am thinking a bad relay or circuit board somewhere in the genset system. Has anyone experienced this or have any ideas/recommendations?

[wingless]

Welcome to the forum.

Here is the service manual.

https://www.seapowermarine.com/seapowerwp/wp-content/uploads/2018/05/MDKDK-DL-DM-DN-Service-Manual.pdf

Assuming no error codes or blinking fault codes, correct?

Section 9.4.12, page 89, has 15 possible causes for this problem.

Does the low voltage exist with no load applied? Does the low voltage change after voltage is applied?

[Proud_Warrior]

Hi Wingless- Thanks for coming up on the net. I have been following your many posts in the past which are very helpful to us all. I have no error codes of blinking fault lights. The generator appears to be running normally and supplying normal 120vas to line 2. With the genset on no and loads line 1 reads about 62vac. When a load is applied to line 1, voltage drops to near zero from 62vac.

[wingless]

YW

Great info.

My speculation is that either the circuit breaker is bad (perhaps swap L1 and L2 routing to test) or that the stator has failed.

The linked wiring diagram shows one field shared by L1 and L2.

Use a nice multimeter set for measuring resistance, with nice leads, null out the lead resistance, then measure the stator for L1 and measure the same for L2. It should be low, 5 to 20 Ohms.

[Proud_Warrior]

OK, thanks. Will swap line 1 and 2 cb's and go from there. My generator only has 1200 hours on it. I hope it is not a stator as that sounds like an expensive repair. Have Onan stators failed in the past with so few hours?

[wingless]

Note if the stator has failed then a local generator shop can either swap for an already rebuilt part, or rebuild your existing part, for the most cost effective repair.

Yes, it is a butt pain, usually because of access, but also because of large mass.

[Proud_Warrior]

OK, thanks. I would think with all of the diagnostics built into this genset that I would get a fault or code responding to a failed stator winding but who knows. I find it curious though that I am receiving exactly one-half of the normal voltage output from the generator line 1 source at 62vac. If the line 1 generator cb in the salon main cb panel failed, I would think it would either work or not work but this is in between. I wonder if this may be a clue?

[Proud_Warrior]

Wingless- I wanted to close the loop with you and any others interested. The generator power output tested just fine. I found the common lead post of generator CB in the MDP tested bad with an ohm meter. Found a replacement CB at my dealership. Parts manager stated it has been in stock since 2006 and only two available. So this CB does not fail often. When the failed CB was removed I discovered the common lead post separated from the internal circuitry of the CB. It had been making a poor connection which caused the low voltage. It appears to be a manufacturing defect of the CB that has been lying in wait for 14 years. Selecting the generator switch on/off over the years finally separated the post. I have a pic to share but it exceeds the forum capacity in MB. Thanks for your help!

[wingless]

Excellent news! Thanks for the update.