Starter motor
Starter motor
I have finally got round to looking into poor cold starting on my major, what should the resistance be between live and earth when its cold?
Oh yay, look, another seized bolt! Lets get a hammer.....and some kano.....and some cider!
Re: Starter motor
Not sure what you mean.
If you mean the battery posts -- don't even think about it !!
But if you mean the main wire between the starter motor and battery, try this: With all wires in place, connect your voltmeter leads - on a voltage setting above 15v. - between the the connection on the starter motor itself and the live terminal of the battery. Have someone operate the starter. If you get a reading of above point 2 [0.2] of a volt then you have unnecessary resistance in the wire circuit. Clean wire ends, starter connector terminal, solenoid terminals and battery post.
Next connect your voltmeter [on volts] between the starter body/casing and the earth battery terminal. Again, have someone operate the starter. Any voltage reading, other than a slight fluctuation, and you have poor/bad earth connections. If this is suspect, fit a braided earth strap underneath the bolt head of a motor securing bolt and screw the other end onto the end of the earth to battery wire.
If, though, the problem is that the starter is not engaging, or turning the engine over, suspect the electro/mechanical solenoid contacts. Over the years these can become gunged up and not make proper bridging contact. I believe these can be cleaned and re-set - all though I've never had cause to strip one yet.
Assuming, from your post, that when the engine is warm, or hot, everything works as it should, then your problem could be a dodgy battery. Surprising as it may seem, there is less resistance in wires when cold than when they warm up.
Pavel
If you mean the battery posts -- don't even think about it !!
But if you mean the main wire between the starter motor and battery, try this: With all wires in place, connect your voltmeter leads - on a voltage setting above 15v. - between the the connection on the starter motor itself and the live terminal of the battery. Have someone operate the starter. If you get a reading of above point 2 [0.2] of a volt then you have unnecessary resistance in the wire circuit. Clean wire ends, starter connector terminal, solenoid terminals and battery post.
Next connect your voltmeter [on volts] between the starter body/casing and the earth battery terminal. Again, have someone operate the starter. Any voltage reading, other than a slight fluctuation, and you have poor/bad earth connections. If this is suspect, fit a braided earth strap underneath the bolt head of a motor securing bolt and screw the other end onto the end of the earth to battery wire.
If, though, the problem is that the starter is not engaging, or turning the engine over, suspect the electro/mechanical solenoid contacts. Over the years these can become gunged up and not make proper bridging contact. I believe these can be cleaned and re-set - all though I've never had cause to strip one yet.
Assuming, from your post, that when the engine is warm, or hot, everything works as it should, then your problem could be a dodgy battery. Surprising as it may seem, there is less resistance in wires when cold than when they warm up.
Pavel
Re: Starter motor
Sorry, i just read my post! When i did the light restoration work, I replaced all the leads etc. I didnt replace the solenoid.
What i meant in the first post, is what is the resistance between live and earth through the starter windings? It gets hot and turns it over slowly when its cold, its fine when warm.
Its got a brand new 100ah battery on it, so this SHOULDNT be the problem, however i suppose i could have a faulty new one, i will try and borrow a battery tester sometime before i get the starter reconditioned!
What i meant in the first post, is what is the resistance between live and earth through the starter windings? It gets hot and turns it over slowly when its cold, its fine when warm.
Its got a brand new 100ah battery on it, so this SHOULDNT be the problem, however i suppose i could have a faulty new one, i will try and borrow a battery tester sometime before i get the starter reconditioned!
Oh yay, look, another seized bolt! Lets get a hammer.....and some kano.....and some cider!
Re: Starter motor
Nick, may I suggest you remove the starter and investigate the state of armature and brushes. Check that the brushes are not excessively worn down so as to be resting on their holders and that they move freely in their holders. Also that the springs press the brushes onto the armature segments. Check also that the copper segments are clean and not excessively scored. With a bit of ingenuity armatures can be trued up and cleaned; and brushes can be replaced. Bad contact can be a cause of excessive resistance and therefore heat.
If you care to google "Lucas Fault Diagnosis Service Manual" you'll find a wealth of info about checking Lucas components.
Pavel
If you care to google "Lucas Fault Diagnosis Service Manual" you'll find a wealth of info about checking Lucas components.
Pavel