Community Forums

michguy · 03-04-2013, 02:18 PM

My Onan Diesel Generator worked just fine when I last started it over a month ago. Today, when I push the starter switch, it doesn't turn over. My Fantastic Fan is on and slows down dramatically when I press the Gen Starter switch. Any suggestions will be welcomed.

HeapBigEngin · 03-04-2013, 02:34 PM

Without a bit more info, it seems likely that your coach/house batteries are severely discharged. Or, you could have a battery connection/grounding/corrosion issue which can produce the same result. How old are your batts and do you keep them up to charge during storage? Turning any diesel motor requires very high amperage/current. Poor connections/grounds or weak batteries just won't get it done. That's where I would start looking. Hopefully others will chime in with suggestions.

Please let us know how you make out....thanks!

palehorse89 · 03-04-2013, 02:34 PM

Sounds like your house battery's are down, not enough voltage to start it. Do you have it plugged in to shore power? Do you have a meter inside to display the battery voltage? What does it say?

tquarles · 03-04-2013, 02:55 PM

Remember that the onan diesels don't start immediately when you press the switch - you have to wait from 10 seconds to a full minute for the glow plugs to heat up before it'll try to crank.

michguy · 03-04-2013, 03:54 PM

I am plugged into shore power, and the meter at my monitor panel says 12.5. I tried holding the starter switch down, and the voltage dropped quite dramatically, so much so that my Fantastic Fan slowed down and my Carbon Monoxide warning device flashed for low voltage.

palehorse89 · 03-04-2013, 04:03 PM

Quote:

Originally Posted by michguy

I am plugged into shore power, and the meter at my monitor panel says 12.5. I tried holding the starter switch down, and the voltage dropped quite dramatically, so much so that my Fantastic Fan slowed down and my Carbon Monoxide warning device flashed for low voltage.

Sounds like your voltage is down a bit, plugged in you should read 13.4-13.6 vdc if the battery's are up to charge. If you have a meter check the output of your converter to see what the voltage is. How do your terminals look, when was the last cleaning and maintance on them? To notice such a voltage drop with the readout and your fan speed , one of two things maybe, bad connections, bad cells in barttery or battery's. If you unhook them for cleaning might want to haul them to a auto parts shop for load testing to see if one of them has a problem. How old are they?

TQ60 · 03-05-2013, 03:17 PM

If plugged in and only 12.5 then not fully charged...but should be good enough.

Suspect Battery may be bad, will charge to 100% but the capacity is less due to sulfated plates.

Let it charge a day or 2 and try again.

Needs to be 13.5 or so with charger attached.

If you disconnect the charger, just tap the starter or let it sit for a few hours the fully charged Battery will read 12.8

If it works after charging it still should be tested.

Jimooo · 03-05-2013, 03:26 PM

I would start by checking your hot and ground coming from house batteries to gen set, re-tighten all connections until you find the loose one.

Good luck, James

palehorse89 · 03-05-2013, 03:31 PM

A battery can show fully charged (13.4 vdc) and when a load is induced on it , it will drop right down to 4-5 vdc and just make solenoids click. Battery plates shorted out inside. Your fan slowing down and your lpg detector going off is a sign of this.

michguy · 03-06-2013, 06:35 AM

Thanks to all of you. Y'all were right on regarding your battery suspicions. My Coach batteries were at least 5 years old, and badly in need of replacing. 4 new ones yesterday, and we're good to go!

HeapBigEngin · 03-06-2013, 09:08 AM

Quote:

Originally Posted by michguy

Thanks to all of you. Y'all were right on regarding your battery suspicions. My Coach batteries were at least 5 years old, and badly in need of replacing. 4 new ones yesterday, and we're good to go!

Thanks for getting back to us with the update....wish more folks would.