Slick Stick to clean up their generator slip rings

[tpcollins]

I'm still having trouble getting my 1995 Onan generator to stay running. It is 20+ years old even though it don't have more the 360 hours on it - don't know if that's a lot or not.

Issue still is it starts but dies as soon when I let off on the switch. Last year I bought a new control board and that worked last year. This year it's the same old thing

I still think there's a potential issue with the birds nest of wiring crammed into the back of the control box. Before I pull it out and take it to a service dealer, has anyone used the Flight System's Slick Stick to clean the slip rings on their generator? My boy is an electrician and he's looked at the schematics and feels the problem is with the winding used for charging the battery when running. The control board monitors that and if not present it shut down. Could be a brush issue,

So is the brush and slip rings the same thing? If so i'll order this Slick Stick first. Thanks.

http://www.flightsystems.com/p-slick-stick.html

[dougrainer]

tpcollins wrote:
Thanks for the help. I should have mentioned this gen runs off of propane. If there is a window for some good weather I'll bring it back in and see if I can find the brushes and slip rings to see if I can clean them. Hopefully that will help.

There is a black plastic cover at the side of the Armature bell housing for Brush access replacement and the 2 slip rings. Doug

[tpcollins]

Thanks for the help. I should have mentioned this gen runs off of propane. If there is a window for some good weather I'll bring it back in and see if I can find the brushes and slip rings to see if I can clean them. Hopefully that will help.

[dmck413]

I had a 95 winnebago that the generator would do the same. Ended up having a small hole in the fuel line above the tank. Thanks squirrels .

[dougrainer]

The OLD Onans(70's thru mid 80's) did not have a electric starter motor. The had a LARGE Armature that had BOTH DC brushes(slip rings) and AC brushes(slip rings). When you applied 12 volt power to the Onan, the DC brushes turned the Stator/Rotor(Armature assbly) to turn the Genset to starting speed. Then the AC brushes supplied the excitement for the AC output. Now, This OP's genset does NOT have a battery charger circuit IF he has the standard 12 volt starter motor. It DOES have the AC brushes and slip rings. IF the Genset sees NO 120 output power(Usually defective voltage regulator) the genset will NOT stay running when the Switch is let go. Also if the Oil pressure sensing system is defective. Doug

[1995brave]

Issue still is it starts but dies as soon when I let off on the switch

Check your oil pressure switch and oil level.

[allbrandauto]

my onan 5500 did the same thing at 260 hours it was 1 brush were down to nothing I cleaned slip rings and 260 hours same thing I wound up replacing armature if you want to test it pull conectors off brushes and use ohm meter between brushes and cheek for resistance

[MrWizard]

Some Onan genset did charge the batteries, and we're not dependent on the converter, example back in the 70's
idk what model year they made the change and removed the charger section

To the op
Remove the brushes and clean them, a little smoothing on the sides with fine emery paper, you just want to keep them from sticking
When I worked on motors and generators we used a cut to size piece of hardwood to burnish rings and comutators
The field brushes and slip rings in a genset are low voltage low amperage
The seldom pit or burn unless sticking in the holder and not making contact

Sounds like the fuel pump latch circuit is not working
As a test you can put a jumper wire on the fuel pump making it hot and running
And see if the generator stays on
Also check the low oil switch circuit
You really do need to use it more often

With generators the old adage "use it our loose it" proves to be true most of the time

[RLS7201]

You can use a green or red scotch bright on the end of a carpenter's pencil to clean the slip rings.
The brushes are those dark gray carbon pieces that ride on the copper slip rings, that you intend to clean.
Your generator does not charge your batteries. You generator makes 120 volts AC that your converter uses to charge your batteries.

Here is a test procedure offered by to me by Generator Jim.

1. Pull the air filter and remove the brush cover from the generator housing behind the filter.
2. Unplug the two wires that feed the brushes and tape them to prevent shorting them out. Make sure the brushes are free in their holders and the slip rings are fairly clean.
3. Obtain two jumper wires. Connect as follows:
3a. Connect the bottom brush to the frame of the generator set.
3b. Connect to the top brush and leave it hanging free - but safe.
4. Open the two circuit breakers on the output of the unit.
5. Connect a multimeter on the buss bars.
6. Start the unit, observe the multimeter, and connect the one loose brush wire to the battery positive cable on the generator set starter solenoid.
7. This will put 12 volts DC on the stator. It should generate about 65 volts no load at the generator output.
8. If no output voltage, bad rotor and/or stator.
9. If voltage, you have a bad voltage regulator or problems in the wiring to the regulator.
10. Go buy a service manual.

Good Luck

Richard

[Chopperbob]

Its not making power. Find a Cummins dealer.
They fix Onan gens. Probably needs r & r.
RV repair shops dont have the parts.
Caused by nonuse.

[Mandalay_Parr]

Think you need to find out what's causing the shutdown before throwing parts at it.
My gen is 2005 and has 1500 hours which isn't a whole lot.

[Mr_Mark1]

Mr. Tim,

USE the genny!!! That's extremely low hours and might be the cause of your problem. I was at a seminar last year and the guy next to me had 7,000 hours on his 20 yr. old diesel genny and it was purring like a kitten.

You really should use it once a month under at least half load to keep all the parts clean and ready to go. Your average is only 17.5 hrs. a year. We already have 240 hrs. on our 23 month old unit.

I'm trying to put at least 100 hrs. a year on ours. Ours is scheduled for service every 250 hrs.

Safe travels,
MM.