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Discussion Starter #1
So I was given this generator from a neighbor who was older and stated she never used it. Prior to moving the generator to my home I ran it at her home for about 10mins. I also changed the oil prior as it sat for about 10 years. Anyway I moved it to my house where it sat for another year. I recently got the natural gas connected so I fired it up. I noticed that there was some rust on the body of the generator and that some of the grounding for the sensors and solenoids were not functioning because of the poor ground connections. I ran some ground cables and solved that problem. I currently do not have the load side connected.

The generator will start right up and run and sounds good. I noticed that while the engine was running, the starter was engaging periodically. After about 3-4 mins, the engine shuts down and the LED flashed 4 times indicating "Engine start failure." I then found the wiring diagram online and could not see what tells the CPU the engine is running. I connected T1 and T2 wires to the load side of the circuit breaker inside the generator and tried running it with the circuit breaker on. When I do that the generator starts and runs for about 10-15 secs and shuts down. It then restarts and shuts down again continuing this pattern for a while.

When I check the voltage on the line side of the circuit breaker I noticed that the voltage is low (98v / 98v 198v). If I shut the breaker off it goes back to running for about 3-4 mins however cycling the solenoid numerous times. I would manually hold the starter wire on the solenoid till after it started then remove the wire so it would not burn up the starter.

Another note was that the earth ground that needs to connect to the house ground (or ground rod I am assuming) was not connected. It was attached to a lug which was mounted to the generator housing however that rusted off. I ran a new wire to the base of the engine and spliced it for now however there was no change. This occurs in Auto and Manuel mode.

Can somebody point me in the right direction?? Thank you in advance.

Tom
 

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You'll probably need to disconnect the safeties/electronics and start/run the genset in "stupid" mode for a while until the generator recovers from not being run for so long. Monitor the output voltage and it will hopefully rise to about 122-127V on on each leg within an hour or so. Then you can reconnect the electric starter and other circuitry. Had a similar issue with an Onan that sat for 20 years; works perfectly after exercising it as above.
 

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Discussion Starter #3
So your saying bypass the computer completely and run it for a while. Can I jump out the solenoid? Also what shuts down the motor?
 

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So your saying bypass the computer completely and run it for a while. Can I jump out the solenoid? Also what shuts down the motor?
With the switch in Manual mode, you should be able to start the engine without the utility power present. Then pull the starter wire off the solenoid as you said you were already doing to eliminate the constant restart attempts, and wait for the output voltage to (hopefully) normalize. Moving the Auto/Off/Manual switch to Off should shut down the engine.

Link to manual in case you don't have it: https://c.searspartsdirect.com/mmh/pd_download/lis_pdf/OWNM/L0402147.pdf
Link to troubleshooting guide: https://c.searspartsdirect.com/mmh/pd_download/lis_pdf/OWNM/L0402150.pdf
See Page 23 for the Low Voltage Troubleshooting section and follow the procedure there if the simple "run it for an hour" doesn't solve the low voltage issue. Also see Page 24 for the Engine Fails To Start troubleshooting.
 

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Discussion Starter #5
The issue is even in manual mode it shuts down after about 3-5 minutes. I was wondering if I could bypass whatever shuts down the motor itself.
 

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Discussion Starter #6
With the switch in Manual mode, you should be able to start the engine without the utility power present. Then pull the starter wire off the solenoid as you said you were already doing to eliminate the constant restart attempts, and wait for the output voltage to (hopefully) normalize. Moving the Auto/Off/Manual switch to Off should shut down the engine.

Link to manual in case you don't have it: https://c.searspartsdirect.com/mmh/pd_download/lis_pdf/OWNM/L0402147.pdf
Link to troubleshooting guide: https://c.searspartsdirect.com/mmh/pd_download/lis_pdf/OWNM/L0402150.pdf
See Page 23 for the Low Voltage Troubleshooting section and follow the procedure there if the simple "run it for an hour" doesn't solve the low voltage issue. Also see Page 24 for the Engine Fails To Start troubleshooting.
Thanks for the schematic it helped out big time. I will just disconnect the one wire that shuts down the motor and monitor the temp and oil.
 

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Discussion Starter #7
Just an update..

I replaced both 35uf capacitors and got the voltage up to 237 on both phases. The generator however, still shuts down and I get the "fail to start" warning. I jumped out the CPU and ran it without any safeties. The Genset runs fine and the voltage maintains. I still however get the fail to start warning. I ran the Genset for over an hour. The frequency is also at 60hz. I have not had a chance to load test it yet however this Hurricane almost forced me to.

Just wondering what else could be setting off the fail to start warning.

Thanks
 

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Sounds like you're chasing intermittent symptoms. The ground issues would hint that weather and rust have likely compromised electrical connections causing the problems.

You don't fix "poor ground connections" by "running some ground cables." You fix the poor connections. Inspect and as needed, disassemble, remove corrosion, rust, etc., adjust or replace, apply some anti-corrosive/preservative like DeoxIt, and reassemble.

If you have "poor ground connections," you probably have lots of other poor connections elsewhere. Same procedure applies. Inspect and as needed, disassemble, remove corrosion, rust, etc., adjust or replace, apply some anti-corrosive/preservative like DeoxIt, and reassemble.

This is not guaranteed to solve your problems, but it is a vital first step in the troubleshooting process.
 

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Discussion Starter #10
I guess what I meant was I went through the grounds and installed new wiring from each ground point I saw (I might have missed one) and did not go through the metal enclosure for any of the grounds (there is one however for safety however it there is a poor connection it wont matter for operational means). They all loop out and go back to the battery and to the house ground where necessary. I will go through them again.


As far as going through Page 24-29. I did go through it and read it carefully. Its been a while since I messed with this however I believe I was getting 60hz to wire #66 Pin #10 . They also dont mention anything about my issue in the Manual which leads me to believe that if I was getting the sensing freq to the CPU, then the CPU might be crapped out. If that is the case I am going to run it bypassed because this genset is old and I would rather put the money towards a new one down the road.
 
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