onan runs but does not make power

[bill emery]

  we had the gen running for a while today. it was running a little rough. when i turned the ac on it worked for a little while but shut down by it self. i looked at the breakers on the coach and flipped them back and forth. only one 20 amp was flipped when i first looked at them. there are no breakers on the gen itself. it is a onan 4000 in a 1985 rockwood class c. there is a overload button on the gen but i cant seem to push it in. it has alot of play in the button . any ideas on what i did to mess this thing up? thanks for any help

[Richard W. Cobbs]

Not much info, if breaker is tripped, it should mean something overloaded that circuit (unless it is a GFCI type breaker).  I guess, the first step might be to isolate the genset (flip all genset breakers off) so there is no load when trying to start the genset.

RWC

[John "T" Nordhoff]

 Im not smart enough to diagnose this over the net with such little info, heck its hard enough if there. There are a couple issues, when you say it shut down, you mean it quit running altogether or that it kept running but didnt produce any output voltage???

 

 If it quit running, (cuz shes starving for gas) Ive most often found the carb is gunked up or theres a restriction in the suction line back to the tank or the fuel pump is crapping out. They wont run once the gas tank gets down below 1/4 to 1/8 you know??? If it has gas but stops firing Ive found coil or points problems.

 

 If the motor runs but no voltage that gets more complicated and expensive and I cant help over the net and doubtful even if there. Evey Onan Ive owned had a breaker right there on the unit although they are sorta hidden on some models. If it runs but no voltage look for it.

 

 Youre probably gonna have to take this to a shop if youre not experienced on those gensets.

 

 John T

[bill emery]

 sorry for so little info everyone.. turns out the auto switch for the shore power to gen. fried. we replaced the switch and everything works fine for now. when it fried it locked on to shore power and that is why the gen did not make any voltage. with no load on gen it wont make anything.  thanks

[John "T" Nordhoff]

  Thanks for the update, thats why Ive never used those "Automatic" switch over relays, just something else to go bad lol I have a 30 amp RV receptacle fed by my Onan genset in the box where the RV cord is located so when I unplug from shore power and roll the cord up in the storage box I simply plug it into the Genset output receptacle ready for down the road or dry camping.

 

 John T