Onan Quiet Diesel Generator Error Code 46

I had orignally posted this problem under the Talkback forum, but under advice am reposting here.

I have a 2005 Winnebago Vectra 36RD with an Onan RV Quiet Diesel 7500, Model SQDHDKAJ1145H. On our last trip, after arriving at our destination, I tried to start the genset and it would not crank - silent, would not turn over. Instead I got the error code flashes on both the Dashboard and Genset siwtches. After checking it gave me 4 + 6 flashes (error code 46) which the manual says is low voltage and suggests checking the batteries and cables.

I then checked my batteries which were fully charged, the battery terminals and the battery cables on the back of the genset. I checked voltage at each point and although there was slight corrosion on the cables connecting to the back of the genset, I cleaned them good and reconnected. After insuring that I had good battery power and connectivity, I removed the inspection plate on the Genset for the coolant and fuses, checked the three fuses with a circuit tester. All three tested good, I replaced them and got the same result - error code followed by 4 flashes then 6 flashes?

I have been fortunate that we are connecting to land power each night which charges the batteries. I also tried connecting a 12-volt battery direct to the terminals at the rear of the genset - bypassing the house batteries and cables and had no luck. Any help is appreciated!

Glenn Bonner
2005 Vectra 36RD
Re: Onan Quiet Diesel Generator Error Code 46

I checked the trouble shooting manuel. If you are sure the battery and or connections are ok then the only other thing they list is the controller. The controller/ inverter contols everything from starting to charging. I don't know for sure but my guess would be it could be an expensive part. Also I would check wiring at the controler before replacing it. You might get lucky and find corrision or a broken wire. If not you might want to check and see if there is any waranty left on the unit. Hope this helps.
Good Luck
Re: Onan Quiet Diesel Generator Error Code 46

Bush70: Thanks, I checked all of the battery connections at the charger/inverter as well as the battery relays (my relays have fuses on both sides that I checked as well) I am assuming if the error code is true that I would have solved the problem (of low input voltage) when I connected a fully charged battery to the Genset 12V input terminals. If the error is really related to the 120V output side, I have not checked any of those connections.