Starter circuit problem

[pycoed]

I just read a little about starter repair. It said when tapping on the starter makes it work, the problem is usually the starter. It said one of the most common starter problems is the copper contacts need to be replaced. Looks easy, just have to find the parts. A rebuilt starter for this tractor is $400, so I will soon be adding starter rebuilder to my resume.

I've just been through all this twice! First time ( old tractor was new to me -I'd had it one day) the starter switch didn't disengage the starter & the result was a burnt out set of field coils. Took the starter to repair shop(those field coil pole pieces are an absolute B***** to remove if you haven't got the pole screwdriver) & got a rebuilt starter with new solenoid, brushes, overrun clutch & fields plus polished armature. Would hardly start the old girl, so I put my diesel car battery on it: same result, changed all the battery leads: same result, checked everything with the meter, everything checked OK but the starter was still sluggish. Couldn't be the starter that was new?
Sometimes it wouldn't start at all, others it would JUST start it. Took starter off & back to the shop - they found one brush stuck up, so had to repolish the commutator & were very red-faced about it!
4 working brushes & the original battery now spins it up first time every time! Check your brushes - if the starter was as awkward as mine to get off, you can usually just remove the end cover in situ to inspect/renew them. Other thing it might be is bad connection on the solenoid power contacts inside. Solenoids are cheap enough, may be able to change that without removing the starter too, though if it comes off easy, all this is a piece of cake on the bench

 

[SPYDERLK]

Starter trouble does not fit the original symptoms you reported. Your battery tho, at 12.2V quiescent, was iffy. Have you checked the charging system. Stand back and assess well. It will save you money.
larry

Dont rebuild anything until you know what is wrong. It may be that I misunderstood your description of the symptoms, but as interpreted it cannot be anything but a cable. With a slight mental leap in imagining where you measured, it could be the solenoid. Unless Murphy has struck you multiply with a sledge, the starter itself is not involved because that would have required several problems to manifest simultaneously to match the described symptoms.
larry

 

[patrick_g]

Larry, Like Sherlock Holmes, I am not a big believer in coincidence but when all the impossible choices have been eliminated then whatever is left, however improbable, is the truth.

Given time there can be destructive interactivity in the battery related components. An internally corroded cable from acid wicking into it can interfere with cranking and or charging. If cranking is not optimal then the overall load on the batt increases as well as that on the alternator. I have had a marginal alternator eventually take out a batt and vice versa. Before I got over my strong (near maniacal) desire to find the single culprit, I would try to only change THE SINGLE BAD PART. I was overcome by a gust of reality with a lifetime alternator that I had to change out 3-4 times in 18 months along with the batteries it ruined (two at a time as it was a diesel pickup.) I had a similar problem with my Dakota when the wife had to have a new alternator installed when she made a round trip to Iowa and I had to change out the starter.

Luckily, most of the time troubles come one at a time but every once in a while two or three components (especially if there is an intermittent involved) can lead you on a merry chase.

I'm anxious to get the final SITREP and see what all needed to be replaced and what if anything got replaced but wasn't needed.

Pat

 

[Laneman950]

Still having trouble after starter repair. I cleaned the solenoid plunger disc and replaced one contact for $5. Other contact and plunger just needed light cleaning. I kind of doubted this was the problem, the starter parts looked pretty good. Here's what I've done so far. When I was only getting 4v when the key was on, I replaced the battery and the positive cable, cleaned all contacts. Neg cable looks perfect, tests good with ohmmeter. What I haven't done is replace the neg cable (which looks and tests good), the ignition switch, the starter brushes. It's time to get the meter out once again and try to figure it out. Last meter test showed full voltage at starter end of cable when key turned, so one problem is gone. Cables have almost no resistance, no corrosion, pos cable is new. Any advice is welcomed.

 

[FULLPULL]

I ask what kind of tractor and close to the year model?

 

[RickB]

Kinda depends on where you attach the ground lead of the meter. If you use the neg battery post, you are not testing any of the ground path. Grounding the meter on the starter chassis includes the entire ground path in your voltage test. My favorite battery and cable tester is a cheap 100 amp hand held load tester. I test each cable and connection and the complete grounding path according to where I connect it. Much more accurate than interpreting voltage readings.

 

[FULLPULL]

If your tractor has a generator then it could need to polarized then it would charge again . Just a thought. Some older tractors had a positive ground also around 1950 some of us would know if you tell us the tractor model.Thats why i ask.

 

[civesnedfield]

Still having trouble after starter repair. I cleaned the solenoid plunger disc and replaced one contact for $5. Other contact and plunger just needed light cleaning. I kind of doubted this was the problem, the starter parts looked pretty good. Here's what I've done so far. When I was only getting 4v when the key was on, I replaced the battery and the positive cable, cleaned all contacts. Neg cable looks perfect, tests good with ohmmeter. What I haven't done is replace the neg cable (which looks and tests good), the ignition switch, the starter brushes. It's time to get the meter out once again and try to figure it out. Last meter test showed full voltage at starter end of cable when key turned, so one problem is gone. Cables have almost no resistance, no corrosion, pos cable is new. Any advice is welcomed.

You are off to a good start rebuilding the starter but you stopped short. Take off the back cover off and take a good look at the brushes. Chances are they are worn along with the communtator on the armature. My dad rebuilds for a living and does not believe in messing around with just one thing. If ya got the starter off the tractor don't mess around do a complete rebuild.

 

[cpdtwo]

I have the same trouble as posted. replaved the starter and it does not turn over the motor past a compression stroke, it just stops. had 2nd starter sent out and no differece. both where staters that where replacement one for my model. now I'm waiting for the correct starter, or so I hope. I had replaced the cables and battary and with a jump and new battery it stil only turns over and starts once in a while. Could the ingnion switch be the problem by sticking. I do not think it would be the charging system as with the jump there should have been more than enough amps to turn over the starter. as there in nothjing else but the switch or starter what could it be?

 

[SPYDERLK]

Still having trouble after starter repair. I cleaned the solenoid plunger disc and replaced one contact for $5. Other contact and plunger just needed light cleaning. I kind of doubted this was the problem, the starter parts looked pretty good. Here's what I've done so far. When I was only getting 4v when the key was on, I replaced the battery and the positive cable, cleaned all contacts. Neg cable looks perfect, tests good with ohmmeter. What I haven't done is replace the neg cable (which looks and tests good), the ignition switch, the starter brushes. It's time to get the meter out once again and try to figure it out. Last meter test showed full voltage at starter end of cable when key turned, so one problem is gone. Cables have almost no resistance, no corrosion, pos cable is new. Any advice is welcomed.

Does the solenoid click everytime you turn the key? The solenoid is an electromagnetically actuated switch. The batt + cable connects to one side of the solenoid and the starter itself is isolated from this connection when the solenoid is not closed. That click is the solenoid closing. This should be connecting the 12V you are measuring, at the end of the + cable .. the input of the solenoid, to the other side of the solenoid in order to energize the starter. You should be able to see the solenoid output to the starter. It may be another large terminal .. near identical to the one the + cable is bolted to--a picture would help. We want to know 12V is getting to this output terminal. There should also be a 3rd terminal on the solenoid, smaller than the others. This is the one you switch power to with your ignition switch. When +12V is connected here the click happens and the power formerly isolated at the input is connected across to the output. The starter should run if the +12V is making it to the output. Find this output point. Measure from this point to the body of the starter. The meter should read 0v before the click, and about 11V with engine cranking after the click. If it reads 12V and the starter does not run it is probably your brushes hanging up [or maybe worn out if its an old tractor]. If the output point continues to read zero or jumps to just afew volts it is the solenoid not closing properly, or its your ground lead. To test the solenoid, put your meter across the 2 big terminals on it and turn the key. This indication should be 12 before the click and very close to 0 after if the solenoid is closing ok. Be sure to not use ohm setting on an energized circuit. Use V only
larry