My wife and I recently purchased a 93 Dutchman Class C motorhome. It has an Onan 4000 Genset that has started and run well for the last 6 times we have started it. I recently tried to start it and nothing happened. After troubleshooting I found that I do not have 12v to the control board, the 5a fuse is good and I have 12v to the starter relay. Where does the control board get it's 12v power from? Thank you for any help!
Generator problem
- Thread starter inga
- Start date
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Water Dog
Well-known member
If it is an Onan Emerald, and if memory serves me correctly, The board receives 12 volts from a wire from the starter solenoid on the battery post (large one). The solenoid has an internal jumper from the battery pole to the secondary pole ("s") to engage the solenoid. Unlike Ford starter solenoids, the secondary wire (the one on the "s" terminal) should be hot continuously and goes to the board. The board then grounds that wire to complete the circuit for the starter solenoid.
There is a good troubleshooting guide here that will specify the pin numbers on the wiring harness and board if you have the model # of your generator.
There is a good troubleshooting guide here that will specify the pin numbers on the wiring harness and board if you have the model # of your generator.
BrotherBill
Well-known member
The solenoid will receive +12v from the battery at the large post on the right side of the solenoid. This is the post generally closest to you as you face the genset. The control board receives it's +12v voltage from the small post nearest to this large post. When the start button is depressed, +12v voltage is supplied to the small post on the left side of the solenoid and charges the solenoid, closing the contacts and supplying +12v to the starter through the large post on the left side of the solenoid.
Now, to back up just a bit. When you say nothing happens, explain "nothing". Is the genset not turning over? Is it turning over and not starting? Is there a clicking noise when you push the start button? Have you tried both the onboard start switch and the remote switch (if equipped)? A little more information would be helpful.
Now, to back up just a bit. When you say nothing happens, explain "nothing". Is the genset not turning over? Is it turning over and not starting? Is there a clicking noise when you push the start button? Have you tried both the onboard start switch and the remote switch (if equipped)? A little more information would be helpful.
Hello Brother Bill,
I can't thank you enough for responding. The generator had been troublefree until I recently pushed the remote switch and heard nothing. I then went to the generator and tried to start it at the onboard switch and found the solenoid was chattering but the generator would not turn over. I tried it several times with the same result. I then checked power and found I had 12.5 vdc to the large post from the battery. While trying to troubleshoot the problem I found that often times when I would push the start switch nothing at all will happen as if the solenoid isn't pulling in either. I continue to wonder if I have a bad battery without enough cranking amps, although I jumped the house battery to the truck battery and tried to start the generator with the same result. I found a receipt for a new generator control board which was apparently replaced in 04. I would greatly appreciate any advice or ideas you may have and hope that I could replace the favor some day.
Thank you, Dave R.
I can't thank you enough for responding. The generator had been troublefree until I recently pushed the remote switch and heard nothing. I then went to the generator and tried to start it at the onboard switch and found the solenoid was chattering but the generator would not turn over. I tried it several times with the same result. I then checked power and found I had 12.5 vdc to the large post from the battery. While trying to troubleshoot the problem I found that often times when I would push the start switch nothing at all will happen as if the solenoid isn't pulling in either. I continue to wonder if I have a bad battery without enough cranking amps, although I jumped the house battery to the truck battery and tried to start the generator with the same result. I found a receipt for a new generator control board which was apparently replaced in 04. I would greatly appreciate any advice or ideas you may have and hope that I could replace the favor some day.
Thank you, Dave R.
Water Dog
Well-known member
First thing is to make sure your battery connections are clean and tight on both the generator end and the battery end. If they are, and you are sure that your battery is in good shape, use a volt meter and see if you have voltage on the big post on the solenoid (the big wire that goes to the starter) while pressing the start switch. If you do, then it's most likely a bound up starter drive. If you don't (but there's voltage on the other big post, and the solenoid is making clicking sounds - battery cable side) then the solenoid itself is most likely the culprit.
