WTH did I do?

Greetings,
OK gang. Confession time... Recently, I tried starting our Onan generator in anticipation of a cruise. She hadn't been started for quite some time. Hit the pre-warm/glow plugs for a minute or so and...GROOOAN...Hmmm...Tried a few more times and same sad groaning.
I experienced a non-start issue 2 summers ago and a simple shot to the starter motor (SM) with a MFH (Medium F'n Hammer) and she started right up on THAT occasion.
This time, sounded like not enough battery power. Hmmm....Batteries right up. Connections up to the point of the sound shield tight and clean...
Okey-dokey, sound shield off.
The rocket scientists who installed the genny put it on the port side within 4" of the hull so that meant the back was NOT coming off as I couldn't reach the screws at the bottom of the shield. No problem, I wedged a trusty cedar shingle between the valve cover and the shield providing just enough room to get one eye and one arm into the void.
With the telephone assistance of another TF member who shall remain nameless (Ya see Mr. Ski, I told you I wouldn't mention your name) I/we determined a high resistance connection between the solenoid and the SM. I have the burn/blister on my thumb to prove it.
As I mentioned, I couldn't really get a good look at that connection. No problem, SM off.
Bench cleaned all connections and greased them up well with conductive grease and after some contortions, got the SM back in and re-connected. Ta-da!!!! No joy in Mudville tonight Same groaning no start.
Ok, on suggestion of nameless member, SM back off, and the end cover off. Hmmmm.....looks pretty clean, no burnt smell, commutator nice and clean, lots of brush left. SM back in again. Pre-heat, start and....Ta-da! We now have power on the water....BUT, yes BUT....I didn't really find anything wrong and I didn't do anything other than remove and replace the SM twice.
So, the point of this particular epistle is YOUR confessions of not fixing anything and achieving a successful outcome and thanks again TF (nameless) colleague.

The world's most uncomfortable staring contest....

Between the maintenance chief and the Piot in Command when the maintenance gripe is signed off as "could not duplicate on ground"...

It is also the biggest issue I have (really used to have) with my genius son. He would say "I fixed it" and I would ask what was wrong and he would say "I don't know but it is working".

I would say that's right...it is working but "YOU DID T FIX IT unless you know what was wrong and what is right now"

So yes...I hate that you don't know..but the reality is all you can do is monitor and look for patterns/changes.

Did you wire brush the SM to engine block ground surface? All of the starter current passes through that steel to steel joint and bolts.

I did have a starter on my Lehman getting finicky....finally no start....took it in for a check and a very trustworthy guy said time for a rebuild...

Of course it did look as if coolant may have gotten in there in past years under the PO.

Might want to pull it and take it to a starter shop for a look see if it's seen it share of starts. No start after sitting awhile...a little internal corrosion?

Greetings,
Mr. HW. Yup. One of the very first things I do when doing anything electrical is check the grounds. It's quick, simple, easy and cheap. I'm not REALLY concerned about not knowing what I did or how I "fixed" it. It works now and I'm content with that. The mildly frustrating part is I don't know how or what I did. The good thing about this whole exercise is I have a bit more knowledge about the Onan and it also allowed me to clean up the unit a bit.
My reason for posting is that this phenomenon has happened to me in the past several times and I'm pretty sure it's happened to most of the members here at least once. I was just curious about what YOUR "head scratcher" was.
Mr. ps. Just read your post. Nope, looked pretty good both outside and in. I didn't pull the armature, just took off the end plate and had a look-see. I suspect from the condition of the insides and the different color paint on the outside it had been serviced/rebuilt in the recent past (not by me). Onan=white paint. SM=black paint.
Mr. Ski suggested maybe one of the brushes got hung up and my manipulations freed it up.

The gremlin came, the gremlin went. Strange things, those gremlins.

If you didn't fix it (nothing identifiable anyway), and it's working, then clearly it wasn't broken.....until the next time you don't fix it.

Ted

I'm with OC Diver on this one!

More like this

RT Firefly said:

My reason for posting is that this phenomenon has happened to me in the past several times and I'm pretty sure it's happened to most of the members here at least once. I was just curious about what YOUR "head scratcher" was..

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While this has happened occasionally to me in the past--- usually on vehicles-- I soon learned that while I may think the problem has "solved itself," it never has, and it soon comes roaring back to demonstrate itself again with a vengence.

So I learned to use the time between "fixed itself" and "now it's back" to think about the problem and analyze it from as many different angles as possible. So that when it does come back I usually have one or more theories as to what's wrong. Usually one of them turns out to be the answer.

We had an intermittent starting issue on our Onan MDJE a few years ago. The issue wasn't that it turned over slow, but that it didn't turn over at all. Then a day or so later, it would turn over just fine and be like that for a few months before it wouldn't turn over again.

I knew better than to think it was "fixed" so I figured it was either the solenoid, which on this model generator is mounted on the starter, or the starter motor itself which might have a "bad spot" in its rotation which, if it happened to stop there, put it out of contact.

Eventually, it failed to turn over and never resucitated itself. The cure was to have the electrical shop we use pull the starter (a major job in this particular boat) and have it completely rebuilt.

OK RT - I'll join in. But, I have a pretty shitty "tail" to tell.

Suddenly while at anchor in a favorite spot a few miles from our marina, out of the blue (color of our sanitizer/bacteria additive), one of our heads' totie stopped activating when elect button was pushed. It was the one in forward state room (commonly called V-Berth) And yes, it really needed to be flushed into holding tank. So... I first checked all connections in head area and still no flush. Then while punching button over and over... lo and behold... there was an instant of activation, that sound is very recognizable. The instant was probably 1/10 of a second. So... I figured it's the push button switch (it’s just like a horn button). I loaded into runabout and quickly cruised directly to our marina then drove for miles to a West Marine - then back I went and from inside head and deep under salon sole I hooked up the brand new button! Still had a shitty deal! Then under the sole I began to remove every wire and its connector off every contact point for thorough scraping/cleaning/reinstallation. Shitty deal remained. Then I believed, with admiral pushing button while I remained contorted under sole, that I could hear noises inside the solenoid. So. I took my trusty currency tester and did all sorts of tests. By jiminy that must be it! Back into runabout to West Marine… installed new solenoid. No luck! We still had a few days aboard; totie was cleaned by other means than flushing… nuff said. Well, the end of weekend arrived and I went onto bow to pull anchor. Windless had not a peep. Strong arm was the word of the day! Anyway we left for home with Tolly’s forward totie all clean but not functioning and its windless out of wind!

I dwelled on the problem for weeks before we came back to boat. Had all sorts of wires and test items so I could really get into it all and solve the problem. But wait – WHAT Problem??? Totie flushed fine and windless hummed a nice tune. That was over two years ago. Not a problem since. I do have extra used push button and solenoid.

Still shaking my "head" (pun intended) on that one!

Happy Miracle-Fix Days! - Art

chc said:

The gremlin came, the gremlin went. Strange things, those gremlins.

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As someone on another forum said........"darn bilge ferrets"......

Darned electrons! Some days they flow, some days they just run in circles.

A hot terminal means it is high resistance OR it is passing more amps than it was designed for .

Sounds like the starter solenoid might need cleaning or the starter is stuck and using all those amps to sit and smoulder.

Someday you will want to check it out.

Greetings,
Mr. FF. "... high resistance...". EXACTLY. Which is why I carefully checked, cleaned and greased (conductive grease) all connections that seemed or might have been questionable. The reason I removed the SM in the first place is that the terminal I burnt my thumb on (the high current lead between the solenoid and the SM) was virtually inaccessible in situ.
Mr. HW. Before I reinstalled the SM I did paint little arrows on the wires to show the electrons the proper direction to travel in. Maybe that's what did it...
Mr. Marin. I have no illusions that the problem "solved itself" so I must have done something to effect a repair. It just isn't obvious in my mind. As has been mentioned, it could easily be the cleaning of a connection that, although didn't "appear" to be suspect, in fact was.
I did not have to perform this task under duress or bad conditions. I was not limited for time. I did not have to wait for ordered parts. It's ALL good. An educational exercise, if you will.

You had indications of excessive current. You describe groaning, not spinning. Consider that the engine was somehow near frozen and all that work got it spinning again.


I'll leave why it was frozen to your obviously good investigative thinking.

RT - Sun Spots messed with your elect flow! In my case on post # 11 it could be called Bum Spots... that messed with the toilet's flow!

Greetings,
Mr. b. Oh, the engine was spinning alright, just VERY slowly. Never considered a partial seizure. Hmmmm.....Thanks, I think.

I helped Mr. RT over the phone:

First symptom: Slow crank, burning smell. Advice: Check batt volts while cranking, check for hot starter terminal. Volts ok, blister on thumb indicated high resistance at batt cable lug on starter. Starter removed to clean up connection.

Second symptom: Starter back on, no crank at all. Starter removed again to investigate. Advice: Pull back cover on starter to check for hung brushes or other bad condition. Note on many starters, solenoid pull in coil grounds through brushes, so if poor contact, starter will do nothing. Results: Starter internals look good, brushes free, etc. Starter re-installed, works fine, spins over at normal speed.

Only thing I can think of is either one of the leads not back on the right place due to poor access to starter, or a brush or contact had a crappy contact, cleaned up by all the handling.

I just put it in the "whatever" category, it's just a gennie, not mission critical. If it starts reliably from here out, then it's probably ok. If it acts up, time to get the meter and tools out.

It all began with a high resistance connection, and that has been fixed.

Good luck!!!

Eric

Greetings,
Leads in the wrong place? NEVER...OK, maybe once...Not in this case though.
Thanks for all the feedback. So, from all the responses, other than Mr. Art, none of you have experienced this phenomenon? Astounding. I guess I really am "special" OR you're just not 'fessing up. The title is somewhat rhetorical and confession is good for the soul.

Been there, done that. When we bought our boat, it came with an air whistle and and an electric dual trumpet horn. The horn was not working, so I took it apart to see if a good cleaning woud get it going. No good, even when connected diretly to power. Installed a new stainless horn and all was good for that first season. Winter came and went, and when we took the boat out for the first trip of spring, the new horn wasn't working. I checked power at the switch, all is good, checked the switch, seemed to be working. Checked power at the horn, no power. Reconnected everything and tried again at the switch - no dice. Hit the button again, and it was working. This was two years ago, and we haven't had a problem since. The switch is in the pilot house, so no corrosion issues. I figure it had to be a dirty connection in the switch that worked itself out through use, but cannot confirm. Funny how most of these "fixed itself" issues seem to be electrical.

Greetings,
Mr. C. Atta boy. I knew it wasn't just me. Interesting observation about the seeming majority to be electrical. Could be in that case due to not being able to "see" the electrons flowing...

The really good news is that it's your generator and not your engine!

I once had a solenoid that acted intermittently. It was for a time hard to find a replacement so I dismantled it. The internal terminals had eaten away at their contact points. Pulling them out and turning them 180 degrees revealed new contact material that reset the clock so to speak on its age and wear. Not a common repair procedure but I had nothing to lose on this one.

If it were me, I would immediately shoot it with a handheld flir camera such as the seek thermal or similar. Don't have one? Immediately buy one. I have no idea if it will help diagnose where the resistance point is at, but it's the perfect excuse to buy a new tool and will give you something to do while waiting for it to give you trouble again.

Head Scratcher

So with my memorable troubleshooting effort I finally solved it but it took literally a few hours... and trip back to my winter storage yard.
Immediately after launching in the spring and moving to our marina dock I proceeded to hook up dockside power & water and began to flush pink from all the FW lines. After some time I shut faucets etc down & pressurized the system... all OK except the dockside water kept running so I proceeded to put some water in the FW tank & put the FW pump on to see what happened... again got flow to faucets OK but pump wouldn't shut off. Checked bilge and no sign of water anywhere it shouldn't be... same under cabinets in galley, head and FW washdowns at bow & stern. I must have spend another hour turning pump on / off & shore water on/off while listening & again searching bilge & cabinets. Sound of water running while either on & no sound while off!

So lets try a little boater click & clack -
Anyone have a theory??? or better yet had this experience???

Mike, it was I and Tom Overs that started the bilge ferrets thread and you'll be doing us no favours by importing that here!

But there is no other explanation, RT has bilge ferrets!

RT, you are not so "special." Figure this one out;

I proceed to take a shower. Turn on the water and in a minute or two, the float switch rises and the shower sump pump turns on. So far so good. The pump (which is in the bilge--float switch is in the little sump in the shower pan) runs continually. When the water is turned off, the pump keeps running. It doesn't shut off UNTIL, I lift the teak grate from the shower to investigate and it then shuts off instantly. There is no contact between the grate and the float switch. The grate does not even come near the float switch or its wiring, at least 3 inches of separation. Hand operating of the float switch reveals perfect operation.

Must be gremlins. I give up.

Howard

Lifting the teak grate causes enough vibration to cause the float to drop?

Have seen where just stomping a foot will do it for awhile.

If we are going with the high resistance theory why not open the solenoid. If it is the kind where the solenoid both pulls in the drive gear and closes the circuit to the starter that can be c cause of intermittent operation.

RT Firefly said:

Greetings,
Leads in the wrong place? NEVER...OK, maybe once...Not in this case though.
Thanks for all the feedback. So, from all the responses, other than Mr. Art, none of you have experienced this phenomenon? Astounding. I guess I really am "special" OR you're just not 'fessing up. The title is somewhat rhetorical and confession is good for the soul.

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100% Agreed!