Onan Genset won't crank - ideas?

emiddleb · 02-10-2009, 12:50 PM

Hi all,

Looking for some thoughts on what to check before bringing in the mechanic... no help in the owners manual.

RV - 2004 Winne Vectra DP
Gen - Onan 7500 watt "Quiet Diesel" model HDKAJ

Problem - Gen won't turn over. Holding down the start button until the green light stays solid and then pushing "start" just gives a soft clicking (like a relay) coming from the gen. No cranking at all.

Tried the usual suspects - diesel fuel at 3/4, coach batteries start DP engine, house batteries fully charged. (Not sure which starts the genset but both seem ok.) Blinking green light going solid tells me it should be heating/priming ok.

Any ideas what else I can easily check? I'm not a mechanic but do know the difference between a screwdriver and hammer

.

Thanks,
Ed

mjbx5 · 02-10-2009, 02:10 PM

I had this happen with my 4K gasser Onan in my Minnie Winnie. It ran fine while dry camping for 2 days, then just refused to start in the same way as yours. I reached inside, grabbed the flywheel, and managed to move it just slightly. The genny started up just fine and has run very well since. Mine apparently got stuck. It is a one cylinder/plug configuration and found just the right spot in the stroke when I shut it down to hang up.

Robert Rice · 02-10-2009, 04:39 PM

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Sounds like you aren't getting the necessary voltage to crank. Have you tried starting at the Generator? Sometimes this will work. You might also pressing the multi-battery switch while pressing the Generator start button. Let us know what you find.

AFChap · 02-10-2009, 04:49 PM

Ed

Your generator will be set up to start from the house batteries rather than the chassis batteries. It is possible that there is enough battery power to run the pre-heater, etc but not the starter. I see you believe the house batteries are fully charged, but the clicking you hear sounds like insufficient battery power. Did you try holding the battery boost switch down while attempting to start the genny? ...that would bridge the chassis batteries to the house batteries. If it starts then, you will know your house batteries are weak/not fully charged. If that does NOT work, the first thing I would check are battery cable connections at the house batteries and at the generator.

Good luck! Let us know what you find out!

emiddleb · 02-10-2009, 05:03 PM

Thanks guys!

Yes, I did try adding the battery boost when trying to start the gen but no good.

Someone elsewhere also suggested that I check the cable connections at the bottom of the gen, which I will do next weekend when I'm out at the RV again.

Ed

AFChap · 02-10-2009, 05:12 PM

Ed

If you find all the cable connections tight and clean, I would suspect a bad starter. I haven't dealt with that on my Onan so no idea to tell you how to proceed on that on your own...

Jeeperrmartin · 02-10-2009, 05:44 PM

I have had the same problems several times. Once it was a dirty ground, 2 times starter quit.

Izzyblueye · 02-11-2009, 05:28 AM

I had the same problem right after I bought my coach new. Called Onan Tech, they told me to measure line drop from the batts back to the gen. It was about a half volt drop. They told me to clean and recheck all the grounds, which I did. Still did same thing. Then I started the main engine and tried it and it popped right off.
Apparently from setting in the lot the batts voltage dropped enough coupled with line drop it was not enough to start it. Now I always start the engine prior to starting the gen and have never had another problem.

emiddleb · 02-25-2009, 02:12 PM

Since not all do so, thought I'd give a status - Fixed!

Combo of slightly loose ground and perhaps weak batteries.

Tightening/cleaning ground, battery charger for the house, some engine-running time for the coach batteries and gen took off.

Thanks to all for the suggestions! One less thing to deal with before the snow melts.