Generator cutting out

[Brian Sexton]

Having Generator issues with my 2000 Beaver Contessa.  Generator runs fine all night when parked, but after running on the road for a couple of hours, it cuts out and won't say on under load.  Please advise possible issues.  Oil is full, as well as antifreeze.  
Thanks!

[Edward Buker]

Possibly a slipping belt could be the culprit causing an over heating shut down. On my Onan 10kw you will not hear the belt slip so ther is no sign, just a shutdown. If you have or can get hold of an IR gun and aim it at the radiator face and the oil pan after the unit cuts out or after it has run under load for 1/2 hour. The oil pan should be about 150 degrees and the radiator face about 120 degrees if the belt is doing its job. If you see 200 degrees or more then the cooling is inadequate and the most likely cause is the belt. At least you can rule the cooling and belt issue out with some simple measurements.

If you have a fuel filter plugging up it could possibly cause a shut down but that seems not likely given it takes several hours. It may be worth changing the filter just to rule that issue out also. Hope this helps.

Later Ed

[Dick Simonis]

Brian,

A couple of things come to mind.  Since the gen set runs fine stationary that could suggest a fuel problem when underway. Especially if the gen set fuel line happens to share a common pickup from the fuel tank.  Alternatively with a seperate pickup, perhaps the fuel level isn't quite adaquate and the pickup tube sucks some air when sloshing around. Anything below 1/2 tank could cause this problem.  Second would be an electrical problem like a loose connection in the gen set start/run circuit that opens intermittantly while the coach is moving.

Whatever it is i bet it's a simple explanation.

[Bill Sprague]

My 2004 Onan 7500 stores "fault codes".   The first time you do it, reading it will be confusing.  Instructions are in the book.   If you don't have one, try http://www.cumminsonan.com/www/html/Common/pdf/manuals/981-0161.pdf