Onan DJE starting problems -- STARTED WORKING ON 'EM

[ichudov]

A few months ago, I posted a message that my Onan DJE pictured here:

http://igor.chudov.com/tmp/onan/Diesel/

has developed starting problems. The problem is that when I flip the start switch, it makes a loud CLICK as the solenoid pulls back and pushes the gear forward, the the starter usually does not engage.

The problem got worse over time.

I finally found time to work on it (having torrential rains in the area and seeing our friend's basement flood due to 13 hour power outage also helped).

I took the enclosure apart a little.

My finding is as follows.

1. The contacts between positive and negative cable ends, and ther contacts on the genset, were corroded. I corrected that by taking them apart and applying sandpaper pads and using a copper conductive goo.

It did not help.

2. When I engage the starter switch and the gear pulling solenoid pulls back, there is no voltage on the other contact that it is supposed to close when it pulls back (the one leading to the main starter).

in other words, either the solenoid fails to pull back far enough, or the contact inside is bad.

I tried pulling it back by hand as far as I could and measuring ohms -- there is no difference.

So, to me, it is the inside contact that does not work.

I am going to take the starter off and try to open it up carefully in my garage. How can I do it (just take off the wires and the main bolts that bolt its flange to the body of the generator?)

Any words of wisdom?

[ichudov]

If I close the electrical path between where the positive terminal connects to battery, and the terminal leading to the starter, the starter engages. If I do so when I pull up the start switch, the motor cranks.

That's proof enough that the contactor inside the little coil (combo of the contact with the solenoid that pulls the gear forward) does not operate properly.

[Jim Rankin]

I don't know anything about a DJE starter, but I have been into quite a few solenoids. One thing to do first is to remove the starter and make sure there's nothing preventing the starter drive gear from meshing properly with the flywheel ring gear. It could even be a bad tooth or something else wrong with the ring gear. Then with the starter still off, either use jumper cables from a hot battery or reconnect the cable and switch wire, ground the starter frame with a jumper cable or hold it tight to the engine block and try your starting sequence again. If the starter runs this way, and fast with power, you probably have a problem with the engagement of the starter drive or the adjustment (if it has an adjustment) of the depth of travel of the drive before the solenoid contacts close and start the motor spinning. the drive may be bottoming out before the contacts close. Only some starters have any adjustment on the depth of travel. Could also have had a bad ground between the starter and the engine due to corrosion.

Friend of mine got a surprise when he went to remove a "dead" starter from a large gen set his neighbor had one day. As soon as he turned the first bolt, the Detroit diesel fired up on automatic. It had lost the ground and was sitting there, stuck in the startup process, just waiting on the starter to crank when he came along and "fixed" it by moving a corroded fastener so it made a good connection. He said he really learned the importance of disconnecting the battery before making any repairs that day.

If you don't get anything but the same click, shift and then still nothing from the starter motor, look at how the solenoid gets its power and gound. Some are grounded through the starter motor, so if the brushes in the motor are stuck or worn out, the solenoid won't have a ground so it won't even click. Other designs ground the solenoid separately, sometimes through various safety devices etc and if these are all working and allow a crank, the solenoid can shift the starter drive and close it's contacts into a dead motor.

With the jumper cables still connected, touch the motor lead off the solenoid directly with the hot cable to test the motor by itself. Make a good connection, really stick the cable clamp into the stud etc so it gets the amperage through. Motor should readily run and have an even sound without scrubbing, chattering etc.

If the motor runs ok, then disassembly of the solenoid is sometimes rewarding. Many of them can be opened up by removing all the nuts on the studs where the cables and ignition wires hook up. Occasionally there will be a soldered terminal instead of a stud and nut connection, and it must be unsoldered to remove the insulating cap that holds all the studs where the electrical connections are made. Then remove the screws holding the cap to the body of the solenoid and carefully slide the plastic cap off the studs and remove it completely from the body of the solenoid. If it doesn't want to come off, check to see what may still be hanging up or connected inside by looking through the crack as you pull on the cap.

Some of the solenoids are riveted or crimped closed at the factory and take some ingenuity to get into, but most of these can be drilled, sawn, uncrimped etc to access the contacts inside and still be closed back up, resealed with silicone etc and returned to use.

Once you get the cap off, there should be a plunger stem in that end of the solenoid that is pushed when the main magnetic plunger that shifts the starter drive pulls back into the solenoid barrel from the other end. It usually has a bridge disk that is spring loaded onto the stem so it can make contact across some unevenness in the contacts it's supposed to bridge. There should also be a return spring (which may have fallen out when the cap came off) that pushes the contacts back apart when the solenoid looses power.

The contacts are the head of the copper studs that the cables hook to and many times they can be pushed back into the cap and simply rotated half a turn to expose a new surface for the bridge disk to clap into when the solenoid pulls. They can also be flattened by filing if necessary. The bridge disk can also be turned to the other side, but it seldom shows a lot of wear in my experience. Frequently one contact will be eroded while the other is almost new in appearance.

Good luck and be careful.

[B.Ikard]

Igor,

Not sure what spec you have, but I have a wiring diagram/schematic for the 6K YD head model I can fax.....completing my DJE project here as time allows.

My Spec has a manual spring loaded push switch that energizes starter solenoid. The preheat (identical spring loaded push switch) switch must be depressed to provide a voltage path to the start switch in this application.

The battery ground connects to the starter case.

Brent

[Andrew Mackey]

You are telling us that if you short the battery supply to the starter power terminal, the starter turns, and if you apply the starter pawl manually, the engine will turn? correct? Try this - engage starter circut, wait for click of selenoid movement, and then short your starter power terminals. If the engine cranks, then your problem lies directly within the selenoid contactor. Replace the selenoid, and you should be good to go. If you have a GM type starter, sometimes the power terminals can be rotated within the bakelite housing, to extend service life, but more often than not, it's just easier to replace the selenoid. This is how the GM type starter works: When the starter is called for, the selenoid is activated. Depending on starter application, this can either be a grounding contact, or power supplied contact. In either case, the selenoid is energized. This then completes 2 actions - 1st, the powered selenoid pulls an iron core into the magnetic coil that is energized. The core, at one end, is attached to a spring loaded arm that is connected to the starter Bendix drive. The Bendix drive is a small clutched gear that turns the engine flywheel thru a ring gear, when the starter is turning. When the selenoid engages the bendix, the starter motor is ready to turn the engine. 2nd, after the bendix is engaged, the core continues traveling into the body of the electromagnet, and a probe, attached to the other end of the core, then engages a reciever attached to a copper disc that is also spring loaded. This disc is contained within the bakelite end cover on the selenoid. As the core engages this disc, it is propelled toward the outer end of the bakelite cover. On that cover are 2 large copper terminals, that you see from the outside. One has battery power at all times, and one supplies power to the starter. When the core pushes the disc, it in effect shorts the terminals, thus allowing power to be supplied to the starter motor, and off you go! When the engiune starts, power to the selenoid coil is disrupted, and the 2 internal springs return the related assemblies to home position. This first breaks the starter motor power supply contact, and the starter motor stops turning, and the bendix drive and the return spring dis-engage the starter gear from the flywheel, at the same time.

The Ford system operates in a similar manner, but has different ways to accomplish the actions. On the Ford system, the selenoid is remotely located. Its sole action is, when activated, that it closes the battery connection to the starter. It too has a copper disc that makes internal contact between the battery and the starter power terminals, when the internal coil is activated. When contacts are closed, the field cores in the starter are energized. This power pulls a pole shoe (an iron core on a lever)into place, within one of the field cores. The pole shoe is attached to the bendix drive, via a lever and yoke assembly. When the pole shoe is seated, the starter gear is engaged, and a secondary electrical contact, attached to the shoe, is closed, sending power to the starter armature. The starter then turns, starting the engine. When the engine starts, the primary selenoid is de-energized, and power to the starter is interupted. That in turn de-energizes the fields, and the return spring lifts the pole shoe out of the field, dis-engaging the bendix drive, and the armature contacts. Most of the Ford type selenoids are not serviceable - when they are shot, they are dead for good! In either case, the fact that the starter is turning, when you bypass the selenoid, points to the selenoid itself as your problem.

Dis-connect the battery, at the battery! This will prevent unwanted shorts, and sparks! remove the battery and starter power terminal connections from the seleniod. WATCH CAREFULLY where the connections are made. Disconnect the starter activation wiring, note the connection location point on the selenoid. Depending on the application, there may also be an auxillary ignition circut wire as well. If there is, note that connection location point as well, and remove it. If you reverse these connections, the selenoid may engage immediately when the battery is connected. the results of a hi power draw on loose battery connections can be most unpleasant You can now remove the selenoid.

On the GM type, remove the 2 screws or bolts that attach the selenoid to the starter, twist about 45 degrees, to clear the starter motor power connecter, and slide it off the selenoid core. Degrease/oil the entire area, with electrical contact cleaner, and re-install in reverse order.

On the ford type, the same procedure applies, only, you just have to unbolt the selenoid from its mounting point, after the electrical connections are removed.
Andrew

[ichudov]

<<<You are telling us that if you short the battery supply to the starter power terminal, the starter turns, and if you apply the starter pawl manually, the engine will turn? correct? Try this - engage starter circut, wait for click of selenoid movement, and then short your starter power terminals. >>>

That's what I did. I found that

1) The solenoid pulls the lever that pushes the gear forward

2) the starter turns when I apply power to the starter terminal directly

3) the next thing I did was, I engaged the gear by using the start switch, AND applied power to the starter terminal. That DID TURN THE ENGINE just fine.

So the problem is that the solenoid does not energize (supply power to) the starter, when it engages.

<<<Replace the selenoid, and you should be good to go. >>>

Are they generic?

<<<Great GM starter description>>>

Your description is on the mark 100%.

<<<On the GM type, remove the 2 screws or bolts that attach the selenoid to the starter, twist about 45 degrees, to clear the starter motor power connecter, and slide it off the selenoid core. Degrease/oil the entire area, with electrical contact cleaner, and re-install in reverse order.>>>

I will do exactly that, I will remove the solenoid, and will try to disassemble it and clean it etc. I will also check the contacts in depth.

I will make great photos of everything before starting, so that I know how to reassemble things back.

Again, if I can buy a new solenoid part -- if it is generic and substitutes exist -- I would greatly prefer that to repairing the solenoid, for reliability reasons.

The time when I need the generator is NOT the time when I can mess with it, it is either very cold, or very rainy.

Thanks a lot!

[ichudov]

You can see the picture of the starter here:

http://igor.chudov.com/tmp/onan/Diesel/646269.jpg

[ichudov]

another picture of the starter

http://igor.chudov.com/tmp/onan/Diesel/646275.jpg

[ichudov]

I found this part: 191-0433-A starter solenoid for Onan. Their price was $59. I decided that it is not that much money and bought it. With luck, I might have it by the end of the week. If this part is, as I hope, new and working, I will swap my solenoid for this one as it is better than fixing the solenoid, etc.


http://www.partsfortechs.com/asapcar...ite-p-337.html


I may fix my solenoid later on and keep owning it as a emergency replacement part.

I will post updates on this repair project, specifically I am going to take pictures and remove my current solenoid as soon as I can get to it, probably tomorrow.

i

[BTPost]

Originally Posted by B.Ikard

My Spec has a manual spring loaded push switch that energizes starter solenoid. The preheat (identical spring loaded push switch) switch must be depressed to provide a voltage path to the start switch in this application. The battery ground connects to the starter case.
Brent

Brent, You have the "Contractor" Version of the DJB/E which is a bit different
than the Industrial, or Marine Versions. The Main Difference is in the Engine
Wiring and the Safety Shutdown System.

Bruce in alaska

[BTPost]

Originally Posted by ichudov

I found this part: 191-0433-A starter solenoid for Onan.

Iggy, Just about ANY Auto Electric ReBuilder can supply you a NEW, or
ReMaunufactured Solenoid for that Starter. If you just call around, there
should be a Rebuilder in your Neighborhood that will have one in Stock.
Just give them the Numbers off the Starter, and or Solenoid, and they
should be able to match it up, or take it to their Counter and the Counter
Guy will just go pick one out of the Bin. These aren't rare at all, and should
be readily available.

Bruce in alaska

[JCarroll]

Igor, your starter solenoid is full of rust and CRA*, get a new one or pull the old one apart and clean it, not to hard.

With some of your projects i've seen you should have no problem.

[Gunny]

Igor:
As others have advised, pull the starter and take it to your local starter/alternator rebuilder and have him rebuild it. Around here, going rate is $45 to $90 depending on how many parts they put in it.
Good luck with it.

[ichudov]

Gunny, instead of a rebuild, my plan is to swap the solenoid. I think that it is a one weekend job. Cost is about same. I think that the starter motor itself does not need rebvuilding, as it works fine.

[Tom Marshall Jr.]

My DJB has a Prestolite starter, parts were available in 2 days for a rebuld. Tom

[ichudov]

Some pictures are here:

http://igor.chudov.com/tmp/onan/Diesel/Starter-Repair/