Onan Quiet Diesel Error Code 46

[glennbonner]

The Onan Quiet Diesel 7500 generator in our 2005 Vectra stopped working and won't start. It displays an error code 46 which the manual says is low voltage. I've checked all of the fuses (3-underneath the inspection panel) and fuses at the battery relays. The voltage across the 12-Volt input terminals checks out at full house battery voltage and I've removed the terminals and cleaned them.

I also tried connecting a 12-volt battery direct to the terminals bypassing the house batteries and had no luck. Any help is appreciated!

Glenn Bonner
2005 Vectra

 

[Gary RV_Wizard]

That's a new one on me!. We would appreciate it if you post the cause of the problem here when you eventually find it, so we will know how to help others in the future.

 

[Ned]

Is the error code 46 indicating low input (12VDC) voltage or low output (120VAC) voltage?  If the latter, then there is a problem with the generator part of the unit.

 

[glennbonner]

The manual says low input voltage (12VDC), Genset doesn't crank, will not turnover - completely silent when I try to start it.  Here's what I've tried so far:

It is anOnan RV Quiet Diesel 7500, Model SQDHDKAJ1145H.

I've checked my batteries (which were fully charged from the land line), 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 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

 

[Terry A. Brewer]

Glen

Since you have determined good voltage to the genset , you will now have to remove the cover & trace the voltage path inside.

 

[glennbonner]

Terry,  Thanks,  I did remove the top cover and could not see the back side of the 12V terminal connections (to check for corrosion) due to access restictions.  After than it is a bunch of wires leading into the electrical panel, everything I could get to easily checked out.  I did find a 1/4 socket that appeard to be left in the sealed unit from the factory!  I'm assuming there is a bad circuit board and that I'll need to take it to an Onan dealer.  -Glenn

 

[Karl]

Glenn,
I checked the Onan site and they don't have owners manuals available for download. Is there anything in your manual about resetting fault/error codes? Maybe they are 'locked in' until reset by some combination of button pushes or disconnecting the battery for a minimum length of time?

 

[glennbonner]

Karl, yes I just checked and noticed they only have the spec sheet and maintenance diagram online.  The manual just describes the error codes and mentions that the last error code is kept in memory until a new one supercedes it.  There is no process to clear an error code, you just have to solve the problem and it will not display again.  I was hoping someone on the forum had seen the problem before.  I can't imagine it only happening to our Vectra.  -Glenn

 

[Karl]

I suggest you call Onan (Cummins) tomorrow and talk to their tech people. They should be able to pinpoint your problem over the phone - maybe. Good luck!