Onan Generator not starting

Good Morning,
My*Onan 3kw, Model # MDJA-3cr-2268v, generator wont start. Circa 1975.*When*I try to start it, it just goes click. The battery is fully charged, all contacts are clean and tight. It does not have a conventional starter but starts using a series field winding. I am not at all familiar with how this works. I suspect that this is the problem with the Onan.*Does anyone have this Onan Generator or have any*information that they could pass on to me so that I can find the issue and get it fixed?*Thanks in advance for any help.

Since no one else is jumping in, here goes:

Did it run recently?

Did it shut down normally last time it was used?

Can you turn it over by hand in both directions?

Does it draw a large amount of current from the starting battery when you hear the click?







-- Edited by RickB on Saturday 21st of August 2010 12:38:23 PM

Lot of volts but no amps?

RickB. Thanks for the reply. Yes it had been running about 3 weeks ago and worked perfectly. It did shut down normally. I haven't tried to turn it over by hand but I will when I get back to the boat today. There*are 13 amps at the starting battery but it goes down to about 7 at the solenoid when*I try to start it.

Second Onan with the same problem, so my friend was able to go right to the problem.
Replace the fuse holder that is near the starter. It may be hard to find, as it is clipped to other stuff and pushed out of sight. The terminals in the fuse holder looked ok, but were the problem.
Worked for both of us.

cpw5 wrote:

RickB. Thanks for the reply. Yes it had been running about 3 weeks ago and worked perfectly. It did shut down normally. I haven't tried to turn it over by hand but I will when I get back to the boat today. There*are 13 amps at the starting battery but it goes down to about 7 at the solenoid when*I try to start it.

Click to expand...

I think those 13 thingies are volts, and since they drop off to 7 it means something is drawing considerable power, or you have some loose or corroded connections. Depends on where you measured the voltage.

You may have some corrosion on the start solenoid contacts or the brushes on the commutator are not making good contact. If you feel OK going that far into it, clean the comm and check the brush tension.

Follow the wiring diagrams with a voltmeter. Check for voltage at each point.

The schematics may look daunting at first but just follow each portion of the circuit from the source to the destination and it will quickly make sense and you can troubleshoot it yourself. If you are not comfortable doing that then you are pretty much stuck with calling out a technician.

Good luck.



*

RickB., Koliver,

Oops! Volts i meant. Thanks for the info. I will be working on it tomorrow and I will let you know how I got along.

Hello same problem for me

cpw5 said:

RickB., Koliver,

Oops! Volts i meant. Thanks for the info. I will be working on it tomorrow and I will let you know how I got along.

Click to expand...

Hello,

I now its an olsd message but I hope you can help me, is the problem you had with your gen solved?

Can you tell me what the problem was because I have the same problem

grt Pieter

Onan mdja 2.5 kw NO START

Hello,

I have a problem with my old geny,

It starts I turn it of....... and it never starts anymore??

The starter relay is clicking, lots of volts and the minus poles of my brushes are verry hot.

Can somebody help me??!!!

thanks pieter (Netherlands)

Easy things first, check the connections, especially the grounds.
Then check the voltage at the solenoid, at the high amperage-to-the-starter-motor side. The internal contacts of the solenoid get corroded and arced and are the usual failure points of the start system. If none of this works, the starter motor probably needs a rebuild.

Hmm, you can try to tap on the starter with a hammer. If the brushes are a little dirty, it might start.

Kevin

Xsbank said:

Easy things first, check the connections, especially the grounds.
Then check the voltage at the solenoid, at the high amperage-to-the-starter-motor side. The internal contacts of the solenoid get corroded and arced and are the usual failure points of the start system. If none of this works, the starter motor probably needs a rebuild.

Click to expand...

Thanks but this is a generator and starter in 1, its new for me but everytime I come a little bid further.

its a 12 v system but the voltage between my brushes on the startersite is +6 v??

That unit has a compression release on the rocker cover. If that does not function, starter does not have enough torque to overcome compression. Unit also needs a good battery and good cables.

Ski in NC said:

That unit has a compression release on the rocker cover. If that does not function, starter does not have enough torque to overcome compression. Unit also needs a good battery and good cables.

Click to expand...

Thanks but Iturnt the pouly and no compresion, good battery and cabels.

strange but why I get 6 volts on my starter??? and smokey whires on the ground cabels of my brushes??

Greetings,
Mr. R. Are you absolutely sure all your high amp connections are very clean and tight? Including the ground onto the block.

RT Firefly said:

Greetings,
Mr. R. Are you absolutely sure all your high amp connections are very clean and tight? Including the ground onto the block.

Click to expand...

thanks for reaction,

yes Iam sure, but I think my starter sollenoid is not working good/defect. so I check that first.

grts

You might be able to bypass the starting solenoid with a jumper cable going directly from the starting battery to the starter. If it cranks then you'll confirm the issue is related to the solenoid.

Thanks I already thry that and is not working , THE minus brushes are getting verry hot I think bad contacts brushes öre there us Also a relay that switch THE current Maybe thats THE problem because starters and dynamo are One in this gen

Thanks for reply and dont stop helping for all of youthanks reiger

I think there are more than one set of contacts in play to transition from generate mode to start mode. It could be one set of contacts not working and that causes a big ampere drain. I don't have the schematics on that thing.

Hello ski nc

Check THE older MessagePad there is a generaal sheet

Thanks

In THE MessagePad before jou have s electrical sheet

Thanks

Yea, saw that. On this screen I can't really read it well enough to troubleshoot.