# Cummins Onan P4300ie



## Hotrod (Oct 18, 2019)

Hello all. Trying to diagnose my generator. Downloaded the manual and got as far as I could today. Figured I would jump on here with the experts for possible quick diagnosis. Gen starts fine. Holds 120v for about 2 minutes then drops to zero volts. Checked ohms of stator, and it passed. Unit has 240 hours on it. I’m just hoping it’s not the inverter since it’s $800. Thanks in advance for any help!


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## tabora (Sep 6, 2018)

Sadly, not a "real" Onan but a rebranded Robin/Subaru engine/stator/inverter (Onan had always made their own engines in the past). 

Did you download the Owners Manual or the Service Manual? Here's the link to the Service Manual which may help out with troubleshooting if you don't have it: https://www.twinslan.net/~n0nas/manuals/onan/914-0503%20Cummins%20P3200ie%20P4300ie%20Inverter%20Portable%20Genset%20Service%20manual%20(11-2006).pdf
Troubleshooting starts on Page 54. It sounds like you have already tested the Stator, so you may find it IS the inverter or the rectifier, based on the wiring diagram.:tango_face_sad:
KU3-10330-11 Inverter
34K-20903-08 Rectifier


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## Hotrod (Oct 18, 2019)

Thanks! Looks like it is the rectifier as I have no continuity on any terminals. Searched the part, and can’t find it. Any suggestions?


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## tabora (Sep 6, 2018)

Hotrod said:


> Thanks! Looks like it is the rectifier as I have no continuity on any terminals. Searched the part, and can’t find it. Any suggestions?


 Looks like all the major parts places have it:
https://www.partstree.com/parts/subaru-robin-34k-20903-08/
https://www.jackssmallengines.com/jacks-parts-lookup/part/robin/34k2090308
https://www.ereplacementparts.com/rectifier-p-2196844.html


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