1993 Onan 4000 generator

Post model and serial number.

The Cummins guys charge a high but upfront and fair price. A control board is an expensive part, diagnosing a problem will take at LEAST an hour of time at 150/hr, and installing a part will similarly take a few hours.

If it is the control board, you can buy your own and swap it out quite easily, but the part will be expensive still.

It could be several other things. The oil sensors are known to fail (and were removed from subsequent designs for that reason). Could be your carburetor. Could be fuel pump. Post model and serial number, and give more details about when this problem started and what it does as it does.

Model and serial number would be nice. With out them people are just guessing.

You have 2 problems
1. The inside remote switch does NOT work
2. The genset dies after starting from the outside switch
3. Both problems may be related. There is a quick connect harness at the genset from the INSIDE switch. Disconnect that remote and see if the genset stays running. If it does, the inside switch wiring is shorted some place. Doug

Flight Systems has e great troubleshooting guide at https://www.flightsystems.com/pdf/onan-rv-troubleshooting-guide.pdf. The 2 main issues that model has is a bad low oil pressure sensor and not generating power. Not generating power can be dirty slip rings, sticking brushes or bad voltage regulator. Voltage regulators go bad because of bad brushes/slip rings.

Called cumin’s they said diagnostics would cost 150 to let me know what it is if it’s the control board about 500for that plus I stalation so basically if it is that about 1000 to fix it they love rv ers huh

HackerAce wrote:
Had this exact same problem and after trying lots of different things replacing the low oil detection sensor fixed the issue.

You can test this by disconnecting the switch but make sure you have oil in the system first.

I meant that you should check the oil level BEFORE disconnecting the low oil level sensor.

Also try disconnecting the cable assembly for the inside start/stop switches and try starting from the generator. If it keeps running then you have a short somewhere in the cable assembly.

Checked the oil it’s full. Guess this will have to,wait till,we get back going to tn to,get away from the storm coming to Myrtle beach so if it’s till here when we get back hahahah I’ll check it out thanks

Had this exact same problem and after trying lots of different things replacing the low oil detection sensor fixed the issue.

You can test this by disconnecting the switch but make sure you have oil in the system first.