Onan Marquis 5500 Genset-year 2000

[phil-t]

Have not seen, in this thread, where you got the trouble codes from the genset.  Nor do I see where you posted your specific model #.

Restoring Fault Code Blinking ? The fault code stops blinking after five
minutes (15 minutes, Series HGJAA). Press Stop three times within five seconds to
restore blinking. Note that the last fault logged will blink, even after the
condition that caused the shutdown has been corrected.

Fault Codes
The genset controller provides extensive diagnostics by causing the status indicator
light on the Control Switch to blink in a coded fashion. Following a fault shutdown,
the indicator light will repeatedly blink one, two, three or four blinks at a time.
? One blink indicates shutdown due to high engine coolant temperature.
? Two blinks indicates a low oil pressure fault.
? Three blinks indicates a service fault. Press Stop once to cause the
two-digit, second-level fault code to blink. (Pressing Stop again will stop the
blinking.)The two-digit code consists of 1, 2, 3, 4 or 5 blinks, a brief pause,
and then 1 to 9 blinks. The first set of blinks represents the tens digit and the
second set of blinks the units digit of the fault code number. For example,
Fault Code No. 36 appears as:
blink-blink-blink?pause?blink-blink-blink-blink-blink-blink? long pause?
repeat
? Four blinks indicates that cranking exceeded 30 seconds without the
engine starting.
Note: Fault Code Nos. 3 and 4 are first level faults. Avoid interpreting them
as second-level Fault Code Nos. 33 and 44, which have not been assigned
as fault codes.

 

[mudshark]

The consensus of everyone I have been talking to over the last few days is I have a carb problem. I can't get a technician out here until the beginning of February. I figure if it is the carb then I might as well eliminate that as a possibility. If that fixes it then I am probably saving a large repair bill. The tech has to drive an hour to get here.

Phil-t
There are no flashing lights. This is a 1999-2000 Onan.

 

[Gizmo100]

The consensus of everyone I have been talking to over the last few days is I have a carb problem. I can't get a technician out here until the beginning of February. I figure if it is the carb then I might as well eliminate that as a possibility. If that fixes it then I am probably saving a large repair bill. The tech has to drive an hour to get here.

I haven't heard anything that would point to the carburetor..As I understand, it will start and run until you let go of the start button. That doesn't sound like carb problems....But then I'm not a mechanic.

 

[Ernie n Tara]

More likely to be:
Bad oil pressure switch
Bad water temp switch
Bad electric output

Almost certainly not the carb. (If you can hold the switch down and it keeps running definitely not)

Ernie

 

[Gary RV_Wizard]

If the genset runs as long as you hold the switch down, the carb is fine. The switch overrides any faults and keeps the fuel pump running, so the best guess is that you are experiencing some sort of fault condition that forces a shutdown as soon as you release the switch.  I'm not expert on that vintage Onan 5500, but most Onans will quit if low oil pressure or no power from the actual generating components.

 

[mudshark]

I appreciate everyone's input.
Back at the beginning of this problem the genny ran for about two minutes and was producing electricity as I had a heater on and the fridge kicked over to AC. Then it stalled and would not run without holding the switch on. As it had not been exercised since the end of September, (many of the campgrounds prohibit the running of generators), it could have sucked in some bad gas in the feeder line.

 

[jubileee]

If your going to shoot the parts canon at it, I would suggest loading canon with a new control board. Dinosaur brand boards are usually $130-150 for older Onans on eBay. Might try removing and reinstalling old board first just to make sure connections are ok.

 

[mudshark]

Thanks jubileee
I did open the control panel and take apart all the connections I could find. Everything was clean so it was not a bad connection. How hard is it ti swap out a control board?

 

[Lou Schneider]

I appreciate everyone's input.
Back at the beginning of this problem the genny ran for about two minutes and was producing electricity as I had a heater on and the fridge kicked over to AC. Then it stalled and would not run without holding the switch on. As it had not been exercised since the end of September, (many of the campgrounds prohibit the running of generators), it could have sucked in some bad gas in the feeder line.

Having the generator slow down and stop while under load stresses the control board and the voltage regulator as it ramps up to full output in a failing bid to maintain the output voltage as the generator's rotation slows.

Meanwhile,  the impedance it's working into decreases as the generator slows, further increasing the stress on the voltage regulator.

Without drive voltage from the regulator, the generator won't produce voltage and the remaining logic in the control board will shut down the engine when you release the start switch.

Many people have lost their control boards by shutting down the generator without first turning off the air conditioner, which is a similar load as the electric heater and refrigerator.

Flight Systems has a free series of very good troubleshooting guides and videos.

If those show you need a control board or voltage regulator, they make their own aftermarket boards that have an excellent reputation both for RV generators and large commercial power plants.  They're available at  www.flightsystems.com/standby-generator-ats-controls/onan-regulators-and-controls.html.

I wasn't aware Dinosaur was also making Onan replacement boards, they have an excellent reputation as well for their replacement RV furnace and water heater control boards.

 

[mudshark]

Thanks Lou
I have had no luck navigating the Flight Systems website.
Amazon has a control board in stock for Onan-300-4901.
Anyone know if this will work in my generator?

 

[Charlie 5320]

Why don't you call flightsystem and talk to one of their techs? Better than just changing parts hoping you get the right one. There are also some trouble shooting guides on the net, I found quite a few a couple years ago when my buddy and I were working on his onan 7000.

 

[mudshark]

OK, I hate to beat this dead horse but I thought the forum would like to know.
I did call Flight Systems and talk to Tom and I watched one of their videos. He had me do a test and it points to the governor module. I will have to dig it out and send it in for testing. I did get the genny to run by grounding a pin so we are zeroing in on the problem.

 

[Gizmo100]

OK, I hate to beat this dead horse but I thought the forum would like to know.
I did call Flight Systems and talk to Tom and I watched one of their videos. He had me do a test and it points to the governor module. I will have to dig it out and send it in for testing. I did get the genny to run by grounding a pin so we are zeroing in on the problem.

First thanks for the update
And 2nd your not beating a dead horse...Your beating a dead genny ;D

By updating your status on this problem your leaving a solution for someone down the road.
I don't know enough about generators to be of much help. But I'm following your progress in case I find myself presented with the same problem.

 

[mudshark]

Thanks Gizmo
You are right! I would like to beat this dead genny! It felt great to jump one pin and hear it purr again. I found out by taking the governor module out, someone had the same problem with this before. Only one screw was holding it in. I spent a better part of an hour trying to remove a screw that just wasn't there.

 

[Gizmo100]

I spent a better part of an hour trying to remove a screw that just wasn't there.

This is just too funny ;D ;D ;D....Sorry....I shouldn't laugh...But 6 months from now you will laugh every time you think about that hour of your life that you will never get back. ;D

 

[2PawsRiver]

Glad to see progress 8)

 

[Old_Crow]

Thanks Gizmo
You are right! I would like to beat this dead genny! It felt great to jump one pin and hear it purr again. I found out by taking the governor module out, someone had the same problem with this before. Only one screw was holding it in. I spent a better part of an hour trying to remove a screw that just wasn't there.

Yeah?  Wait 'til you try to get the front furnace out of the coach for some reason.  There's a square plenum screwed to the top of the heater case.  Only access is through the return register under the fridge and by removing the drawer under the oven.  Not only are you working on screws you can't see...you can't hardly reach them either. 
Glad to hear you're closing in on a solution.

 

[mudshark]

Well Guys
I sent the governor module to Flight Systems and it checked out good. We are back to square one. Tom, the technician, said the Marquis series of Onan generators are very hard to diagnose. We are now thinking it might be the ignition module which is buried under sheet metal on top of the genny. Almost impossible to get at but I will give it a try...if I can find it.

 

[Gizmo100]

Well Guys
I sent the governor module to Flight Systems and it checked out good. We are back to square one. Tom, the technician, said the Marquis series of Onan generators are very hard to diagnose. We are now thinking it might be the ignition module which is buried under sheet metal on top of the genny. Almost impossible to get at but I will give it a try...if I can find it.

I was thinking about this just yesterday...Sorry it's being such a pain. If you were closer I wold be glad to come over and help cuss at it for you.

 

[mudshark]

Thanks Gizmo
It is past the cussing stage now. I have found a U tube video that explains where the ignition module is and I understand how to get it out. Looks like the unit may have to be dropped down and I have no jack. Once the governor module comes back I will see if there is any way to get at it as is. I also found a link that tells me how to test in if I can get it out.