Generator won't start unless engine running

[Oldchinahand]

Barely a week ago, I was bragging that our Onan 8000 had never so much as hiccuped. My how times change!

Suddenly, the Onan will only start if the Cummins is running. If so, starts right up. From either of the three starting switches.

Will not start while drawing 50amp shore power.

We have two 12v chassis batteries and four 6v house batteries. All less than one year old. All charged and taking a charge. All checked every week or so.

From any of the three starting switches -- on generator, on dash, OneStop -- if the Cummins is not running, there will be the normal pause, then the click of the starting solenoid, but no start. No rolling over.

Have checked everything I know. Likely something simple I've done or overlooked. Any wisdom from experience out there?

Fair Winds and Following Seas

[al1florida]

The main difference that I see is that when the Cummins is running it should be supplying a charge to your house batteries.



You should have a monitor panel inside the RV which shows the house battery voltage (as well as chassis battery). What is the voltage of your house batteries? Then watch the house battery voltage while trying to start the generator using all the various setups you mentioned. What you are looking for is a dip in the voltage showing that the generator is trying to start. If there is no dip in voltage then you have indeed verified that the various switches are not picking the solenoid to start the generator.



Additionally when on shore power or when the cummins is running you should see an increase in the voltage at the house batteries.



Come back and post all the voltages from every test you make. That would help greatly in providing advice on what to look for.

[jerichorick]

Originally Posted by Oldchinahand

Barely a week ago, I was bragging that our Onan 8000 had never so much as hiccuped. My how times change!

Suddenly, the Onan will only start if the Cummins is running. If so, starts right up. From either of the three starting switches.

Will not start while drawing 50amp shore power.

We have two 12v chassis batteries and four 6v house batteries. All less than one year old. All charged and taking a charge. All checked every week or so.

From any of the three starting switches -- on generator, on dash, OneStop -- if the Cummins is not running, there will be the normal pause, then the click of the starting solenoid, but no start. No rolling over.

Have checked everything I know. Likely something simple I've done or overlooked. Any wisdom from experience out there?

Fair Winds and Following Seas

Did you get it going? When the generator fails to start there is usually a series of flashing from the start switch. This is a fault code that can be found in your generator operators manual.

[Oldchinahand]

Rick, Al,

Rude not to have responded. In the interim we lost all 12vdc to our One Stop Center so getting that back on line took precedence. Got it back up. Now have a bruised forehead from slapping it, saying dummy! dummy! dummy! Too embarrassed to say why. Hint. Have been doing some extensive rework of our entertainment system.

Back to the genset. Fixed. Excessive resistance in battery chassis ground. Another forehead slapper. I keep the batteries (4 - 6V), battery cables and genset end posts clean and maintenanced. Dropped the ball on the battery chassis ground bolt. In my defense, you need three doublejointed arms to get after it.

Fair Winds and Following Seas

[Tucsontoy]

Just a thought. My last rig had a 8k in it. It would not start if the fuel gauge was below 1/2 a tank. It would also start if the engine was running as if it was a built in reminder that the tank was low before you stopped to camp, Always thought it was dumb since it carried 150 gallons of fuel.

[al1florida]

Originally Posted by Oldchinahand

Rick, Al,

Rude not to have responded. In the interim we lost all 12vdc to our One Stop Center so getting that back on line took precedence. Got it back up. Now have a bruised forehead from slapping it, saying dummy! dummy! dummy! Too embarrassed to say why. Hint. Have been doing some extensive rework of our entertainment system.

Back to the genset. Fixed. Excessive resistance in battery chassis ground. Another forehead slapper. I keep the batteries (4 - 6V), battery cables and genset end posts clean and maintenanced. Dropped the ball on the battery chassis ground bolt. In my defense, you need three doublejointed arms to get after it.

Fair Winds and Following Seas

Thanks for coming back and updating the solution. No problem for the delay. Glad you got it fixed.



You should see my forehead. It is slapped back to my ears. But then DW slaps me on the back of the head, for dumb thing I do and say, which knocks it back forward.

[jerichorick]

Originally Posted by Oldchinahand

Rick, Al,

Rude not to have responded. In the interim we lost all 12vdc to our One Stop Center so getting that back on line took precedence. Got it back up. Now have a bruised forehead from slapping it, saying dummy! dummy! dummy! Too embarrassed to say why. Hint. Have been doing some extensive rework of our entertainment system.

Back to the genset. Fixed. Excessive resistance in battery chassis ground. Another forehead slapper. I keep the batteries (4 - 6V), battery cables and genset end posts clean and maintenanced. Dropped the ball on the battery chassis ground bolt. In my defense, you need three doublejointed arms to get after it.

Fair Winds and Following Seas

Glad you are a happy camper again. Thanks for the update. Yea. Some of those maintenance points are a bummer to get to. I am way overdo for my electrical polishing. I almost hate to fool with the terminal posts and isolators. Everything is running just fine.



Happy trials,
Rick