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Onan Problem

haste_maker
Explorer II
Explorer II
I have a 7000 watt gas Onan that runs great without the A/C turned on, but sometimes NOT every time it will stop running after the A/C has been on for a few hours...any ideas what the problem could be? I have had both coil packs & the fuel pump & spark plugs replaced.

This generator is in a 2007 32BA gas using a Ford chassis..
Retried Teamster
2007 Allergo
12 REPLIES 12

haste_maker
Explorer II
Explorer II
I cleaned the slip rings, and removed some oil...I was told that some of the Onans had the wrong oil drip stick in them...I did a test run for 20 hours with both AC's turned on without any problems...Thanks to everyone for the advice...
Retried Teamster
2007 Allergo

David0725
Explorer II
Explorer II
I have a onan diesel generator and it did the same thing know one could figure it out. I found out I had a hairline crack in the fuel line I ran a separate line from a gas can and its been running ever since.
1994 Holiday Rambler Imperial DP
1999 Honda Accord V6 Toad

RLS7201
Explorer
Explorer
haste maker wrote:
Thanks for all the input on my generator problem, I have return home & have some tools to check thing with, & I found the slip rings in mine are black not copper, I am going to order the Slick Slick from Flight Systems & clean these rings.


A piece of green scotch bright wrapped around the flat end of a carpenters pencil, will accomplish the same thing.

Richard
95 Bounder 32H F53 460
2013 CRV Toad
2 Segways in Toad
First brake job
1941 Hudson

haste_maker
Explorer II
Explorer II
Thanks for all the input on my generator problem, I have return home & have some tools to check thing with, & I found the slip rings in mine are black not copper, I am going to order the Slick Slick from Flight Systems & clean these rings.
Retried Teamster
2007 Allergo

haste_maker
Explorer II
Explorer II
dougrainer wrote:
test with just the front AC for a few hours. Sometimes a defective capacitor or compressor will load down a Genset and kill it rather than kill the breaker. Doug


I did that today for about 2 hours without any problems, while driving on the road, I wonder if the insulated front cover on the generator and the metal door in front of the generator is casing to much heat while I am parked.
Retried Teamster
2007 Allergo

dougrainer
Nomad
Nomad
test with just the front AC for a few hours. Sometimes a defective capacitor or compressor will load down a Genset and kill it rather than kill the breaker. Doug

haste_maker
Explorer II
Explorer II
dougrainer wrote:
haste maker wrote:
No codes...

Yes it will restart in a few minutes not seconds & run 14 hours or more with the A/C off


Odds are you have a defective rubber fuel supply line from the gas tank. It is old and rotted. When under load the Onan uses more gasoline. NOT under load it may have enough gasoline to run. The best way to confirm this is to connect a gallon gasoline can with a short rubber fuel line and retest. IF it runs under load under load, then you need to replace the supply fuel line. If it does NOT stay running check the oil viscosity, and make sure it is correct and the oil is at the correct level. When you do NOT have a fuel supply problem and the Onan dies, it will then restart with in 10 seconds. But taking longer means the onan fuel pump is trying to deliver fuel to an empty carb bowl. Doug


Doug I am on a trip now but today I started the generator & turned on the front A/C to keep the cat cool while we where stopped to eat, we were only away from the RV about 30 minutes & when we returned the generator had quit, but did start up & I let it run with just the rear A/C on for the next 4 hours while we were driving to our next stop & had no problems..also it now has a code 47 which was the same code it had when I replaced the coil packs & fuel pump & spark plugs...any ideas?
Retried Teamster
2007 Allergo

haste_maker
Explorer II
Explorer II
Thanks I will check into that when I get home, on a trip right now.
Retried Teamster
2007 Allergo

dougrainer
Nomad
Nomad
haste maker wrote:
No codes...

Yes it will restart in a few minutes not seconds & run 14 hours or more with the A/C off


Odds are you have a defective rubber fuel supply line from the gas tank. It is old and rotted. When under load the Onan uses more gasoline. NOT under load it may have enough gasoline to run. The best way to confirm this is to connect a gallon gasoline can with a short rubber fuel line and retest. IF it runs under load under load, then you need to replace the supply fuel line. If it does NOT stay running check the oil viscosity, and make sure it is correct and the oil is at the correct level. When you do NOT have a fuel supply problem and the Onan dies, it will then restart with in 10 seconds. But taking longer means the onan fuel pump is trying to deliver fuel to an empty carb bowl. Doug

haste_maker
Explorer II
Explorer II
No codes...

Yes it will restart in a few minutes not seconds & run 14 hours or more with the A/C off
Retried Teamster
2007 Allergo

dougrainer
Nomad
Nomad
Will it start up within a few seconds(less then 5) when you restart? Or, do you have to crank a lot to get it to restart? Doug

bgum
Explorer
Explorer
Does it throw any codes?
OVER HEATING?