Onan 5500

[bkc914]

unit starts and runs ,,,,,BUT,,,,it either comes online after its delay, or it comes online very slowly, or it doesnt come online at all.
seems like it fails during high humidity

thanks for any info
kevin

[Beau388]

Originally Posted by bkc914

unit starts and runs ,,,,,BUT,,,,it either comes online after its delay, or it comes online very slowly, or it doesnt come online at all.
seems like it fails during high humidity

thanks for any info
kevin

I would venture a guess the the stator brushes are failing.

[Waiter21]

Check the stator brushes, clean the stator.. I serviced mine a couple years ago. I did a short writeup with photos.

Onan Marquis 5500 Generator Service – 1999 Southwind 35S


..

[GREGORYJ]

I have doubts it is the brushes at fault but they are fairly easy to access , remove and visually inspect. You will need to remove the air breather box , they are near the top of the engine, you will need to reach in and remove a single bolt holding the brush assembly in place. When removed, both brushes should be present and slide easily in and out of the assembly , pushed out by a spring on each. The picture of the brush set below shows one brush broken off, the lower one still good. You may be able to pull back the brush assembly enough to look at and check brush movement without removing the wires connected to it. Good luck.
I believe if the brushes are bad, the generator will start and stay running until you release the generator start button, then it stops immediately.

[M&EM]

If the generator runs only while the start button is pushed, than the likely cause is a belt or rubber flywheel coupling. Either case involves gen removal and disassembly..