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ebprod · 06-16-2012, 05:39 PM

My Onan Emerald plus generator was working fine until I stopped to get gas. Ever since then, the little 5 amp fuse on the front of the generator blows every time I try to start it. It cranks for a few seconds then the fuse blows.

I had the A/C on the first time I started having problems, but now it doesn't matter if there is a load or not.

The Motorhome is a 1994 Kountry Aire.

Any suggestions?

-Joel

nightriderrv · 06-17-2012, 05:13 AM

I know it might be a small issue but did you try to start it with the circuit breakers off at the gennie that would disconnect it from the MH elecrtrical system if the problem is there at the gennie then it would blow if it holds then migh be a problem down the line in the MH just a thought.

Jim_HiTek · 06-17-2012, 09:11 AM

There is a delay between the time the genset starts and when it applies AC to the house. Sounds to me like you have a bad control board or a short to ground somewhere before the AC portion of the genset since the fuse blows before it starts.

You might do some resistance checks following the genset guide here: Generator Troubleshooting Guides | Flight Systems, Inc

ebprod · 06-17-2012, 09:47 AM

The fuse blows after cranking for a few seconds, and always before the generator starts. I've tried using the remote starter and the button on the generator. There is a white plug with wires near the switch that I unplugged, but the same result.

I'll look through the documents in the link above.

-Joel

ftv37 · 06-17-2012, 10:09 AM

+1 for the control board, just had to replace one on our Onan Emerald.
Another +1 for Flight Systems, I'm sending mine out tomorrow so they can troubleshoot a problem with their board, and it sounds like they really stand behind their stuff.

camper33 · 06-17-2012, 03:47 PM

I would unplug the harness for the remote start switch, then try again. The remote harness could be shorted, pinched somewhere. If it still blows the fuse, the control board.

ebprod · 06-17-2012, 07:22 PM

I tried it with the remote starter removed- same result. Is there any way to test if the board is bad? Or should I just assume it's bad and order a new one?

-Joel

Quote:

Originally Posted by camper33

I would unplug the harness for the remote start switch, then try again. The remote harness could be shorted, pinched somewhere. If it still blows the fuse, the control board.

camper33 · 06-18-2012, 04:29 AM

I would find the wire that goes to the electric fuel pump and disconnect that to make sure that it is not shorted. After that I would go for a board.

Jim_HiTek · 06-18-2012, 08:42 AM

Quote:

Originally Posted by ebprod

I tried it with the remote starter removed- same result. Is there any way to test if the board is bad? Or should I just assume it's bad and order a new one?

-Joel

I believe that the link above has several tests that you can use to pinpoint the faulty component...or shorted wire. The control board is fairly simple with mostly steering diodes and 3 inexpensive relays on the board, not much there to cause a 5 amp short. Although it might be ruined now, it's so simple, I don't believe it's the source of your problem.

With your symptoms, I'd want to do resistance checks of the other systems before assuming that the board is bad. Especially checks of the generator coils, wiring, Voltage regulator, & diode bridge.

Although the test procedure might seem daunting, doing the resistance checks is the best way to narrow down the problem.

TLGPE · 06-18-2012, 08:59 AM

My coach is an older, simpler model and probably does not have the PC board layout you have, but the fuse is 15 amp (clearly marked). If yours is marked for 5 amp, then you are probably stuck with that, but you may want to check.

Tom

ebprod · 06-18-2012, 09:08 AM

The circuit board says to use slow blow fuse, so I tried using that instead. The generator ran for about 10 seconds then quit. After that it would crank, but not start. The after about 5 more tries, the slow blow fuse blew.

I talked to Flight Systems, and they told me to try disconnecting the fuel pump, coil, voltage Regulator and starter solenoid (one at a time) to isolate the problem. It sounds intimidating, but I will take a closer look this afternoon.

-Joel

ebprod · 05-23-2013, 10:12 AM

Just to update this thread-

I turned out to be the voltage regulator. After talking to the people at Flight Systems, they said that it was probably caused by dirty slip rings. I used their tool to clean the rings, and after replacing the regulator, the generator ran for an hour under load.

I was clued into the solution by another member (Dusty) who had the same problem- thanks.

-Joel