ANOTHER Onan DJE generator starting problem! (Monday)

An update: The shutdown solenoid that must be engaged for the fuel to go to the engine, does not seem to respond to 12V. I supplied 12V via

10 gauge wires, right to the contacts, and the solenoid does not budge and there is no spark when the wires make the contact. Am I trying something wrong? i
Reply to
Ignoramus18778
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It would be easier to measure the voltage across the coil when you try to start it. If the coil does not pull in when the control circuit applies 12 volts, then you most likely have an open coil.

By applying 12 volts from an external source, you risk damage to the control circuit unless you disconnected the coil first.

Tom

Reply to
Tm

Sounds like a dead solenoid - bummer. A re-wind shop may be able to fix it - or you may be able to do the repair. Not all that complex.

Ken.

Reply to
Ken Davey

Just did it. When the engine cranks, there is about 10 volts applied to the solenoid, to no avail.

i

Reply to
Ignoramus18778

Yes, I also cranked the engine and there was about 10 volts on the solenoid terminals, to no avail. I am going to now take it off, take apart, and check in accordance with the maintenance manual.

I would like to fix it DIY, if I can, if not, I will order a new one from a dealer. I have a gut feeling that it is not really dead. I probably messed up something when I took it apart and oiled yesterday. Note that the engine did run very well after I put the solenoid back in. But it would not run the next day.

i

Reply to
Ignoramus18778

Some more pieces to the puzzle.

The solenoid was supplied 10v power during engine startup, and did not do anything. I took it out and applied 12V, nothing happened.

I took the rear cover off and applied 12v directly to the internal contacts. The solenoid started making rattling noises, like a machinegun.

I put the cover back on, it continued to make rattling noise when 12V was applied.

I put it inside the proper slot in the engine and fastened it. Now it would not respond to 12V at all, again.

My feeling is that perhaps by fastening it there, the mechanical pressure and deformation causes something to lose contact somewhere.

i
Reply to
Ignoramus18778

I am now convinced that the problem lies with the solenoid and that it is bad. The rattling and other problems are probably due to the holding coil being bad. The solenoid cannot, to my knowledge, be easily disassembled beyond removing the back cover.

I called our local Cummins NPower dealer and it turned out that the solenoid is affordable, at $36 or so. So, I ordered the solenoid and also flexible engine mounts, I decided to splurge a little bit.

They stock absolutely all parts for that Onan DJE.

i
Reply to
Ignoramus20242

Aha! You didn't mention the 'lube job'. Dissasmble and de-grease. Ken.

Reply to
Ken Davey

Ken, could you tell just what could be bad with the lube job???

I did not apply much oil.

i
Reply to
Ignoramus20242

It doesn't TAKE much oil/grease to foul a set of contacts to the point of rendering them completely inoperable. The question becomes "which way are they going to fail?" in a quick hurry. For a low-voltage environment (and 12 volts definitely qualifies as low voltage), even a film of oil you can't detect can be enough to either act as an insulator between the contact points (assuming "clean" oil) or potentially worse, "dirty" oil can short things out so that the contacts appear electrically closed even when physically wide open. Either way, oiling electrical gear is generally classed as a Bad Thing(TM). Oil the mechanical work, sure. But do everything in your power to avoid oiling *ANY* of the electrical stuff - A drop of oil can short several turns of the solenoid coil, predisposing it to early failure, gum up the contacts that activate (or get activated by) the solenoid, perhaps even strip the insulation off the wiring, depending on what type of insulation is being used.

Reply to
Don Bruder

Thanks, this makes complete sense. Can I, hypothetically now try to remedy this by submerging this thing in a solvent? This is more of a theoretical problem due to two reasons:

  1. The solenoid probably was not working quite right because its holding coil was not working. It was making machinegun like rattling noise from the get go.
  2. I already ordered a new solenoid. It is nice that it turned out that Onan stocks all parts for this generator.
i
Reply to
Ignoramus20242

Maybe, but I suspect that replacing it is going to give you much better results.

I'm thinking that was a sign of the holding coil being bad, and the pull-in coil and it's switch chattering till _they_ gave up.

Too bad mil-surplus stuff doesn't come with a "surplussed for the following reasons" list, along with a maintenance history (which I'd think the military would have _had_ to have had...

Reply to
William P.N. Smith

Yes, and it is a moot point now anyway, given that I ordered a new one already. I will even have it tomorrow.

I agree with that.

The other side of the coin is that it enables people like me to make money (and taxpayers to lose a lot more money).

It is an unholy mess. Sometimes perfect items are surplussed for petty (to me) reasons. I recently bought a dental compressor for $404 and resold it for 3+ times more. All I had to fix was a tiny nipple that fell off from the pressure sensor. The buyer is very happy with what he bought. Do not even get me started on UPSes, barcode readers, etc.

I hope that besides the solenoid, there is nothing wrong with this genset. It does work after all, as I found out on Saturday. Load tested it and all.

i
Reply to
Ignoramus20242

Read The Fine Manual - Solenoids usually don't like any oil in their moving parts, and contrary to intuition it can gum up the works and cause them to stick. It's okay to lightly oil the linkage pivots, but not inside the bore. I learned this long ago from doorbell chimes.

Normally you clean oils off the bore and slug with a solvent and buff them up a bit with very fine steel wool or crocus cloth. If anything is allowed in there it might be a little bit of dry graphite lock lube, or a Teflon spray dry-film lube, something that won't dry out and get gummy on extended exposure to air.

Since you ordered a new solenoid already, check the instructions that come with it...

-->--

Reply to
Bruce L. Bergman

Thanks. I do not think that I saw anything in the manual that would say not to oil the solenoid, but what you say makes complete sense.

I see. Thanks.

I sure will.

Thanks Bruce.

i
Reply to
Ignoramus20242

Is this a Prestolite brand solenoid? Dave

Reply to
Dave Morrison

Yes, it is.

i
Reply to
Ignoramus20242

Okee dokie now we are in my ball field. As you noted this unit has two coils. When you take the back cover off you will see two sets of winding wires. The heavy wires are the pull in coils and the small almost hair thin wires are the hold in coils. Check and see if the thin wires are burnt off. Gotta go now the power company is shutting me down for a while, prepping for my 55kw genset install, will post more info on this solenoid later, including why they fail. Dave

Reply to
Dave Morrison

Solenoid Prestolite SSC 4003, 12V 5L

yes

Yes.

Yes.

They are not burnt off. I see only perhaps 3 mm of them. (the solenoid is in my home, but I remember it pretty well). I have no idea how to pull out the whole thing from the housing.

I greatly appreciate!!!

i
Reply to
Ignoramus20242

Possible contamination of internal swtich contacts?

Reply to
Ken Davey

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