Alternator wiring diagram

[smileypete]

No could not find a 5w lamp so have been starting it ewvery day crossing the two wires on the A & B on alternator, the belt is loose but yesterday I ran engine for about 11 hours and when I put the last post up it read 12.2v HELP! I'll go and try again, hang on, OH its working now so here is results.

 

1. voltage across dom + and - = 12.63

 

2 " " " " " = 13.64 and rising with black jump lead in place

 

3. Jump lead connected to both terminals on split charger -00

 

4. Voltage on domestic with jump leads stll on split charge 13.75

 

5 Jump lead connected to battery and split charger end one 13.72/3

 

Lastly voltage from alternator and casing of alternator 00

Tried last one a few times with everything in place.

 

Well done! That's very very helpful.

 

I would agree with Snibble and the others that it's most likely to be a poor connection somewhere between the domestic battery -/negative and the body of the alternator.

 

Also that the poor connection could be between the alternator itself and the bracket on the engine that it's bolted to.

 

 

So I would recommend testing for the above as follows.

 

Firstly run the domestic batteries down to 12.2v, which is very roughly half flat.

 

Then carefully scrape some paint (about 2p piece size) off the face of the alternator bracket that's between the engine and the alternator, using the end of a flat screwdriver, small scraper or something similar.

 

 

Start the engine and run at normal charging speed, then measure and write down:

 

1. The voltage across the domestic battery + and - terminals.

 

 

Carefully connect one end of the black jump lead to the alternator bracket where the paint has been scraped off, and carefully connect the other end of the lead to the alternator frame/body. Then measure and write down the following:

 

2. The voltage across the domestic battery + and - terminals (jump lead between bracket and alternator.)

 

 

Now, disconnect both ends of the black jump lead from the bracket/alternator.

 

Then carefully connect one end of the black jump lead to the negative/- side of the domestic batteries (that the thick black wires go to)

 

Then carefully connect the other end of the lead to the alternator frame/body, measure and write down the following:

 

3. The voltage across the domestic battery + and - terminals (jump lead between domestic battery negative and alternator body.)

 

 

Switch off the engine, first remove the end of the black jump lead from the alternator frame, then the other end from the negative/- battery terminal.

 

And that's it

 

 

I think the reason the clip on ammeter doesn't work so well near the alternator is because it works on magnetism and the alternator can create a magnetic field.

 

One other thing, I noticed there is a battery isolator on your instrument panel. When the switch is off, can you confirm it prevents the engine from starting at all?

 

(BTW never switch the battery isolator off while the engine is running unless there's an emergency! This is because the the alternator can get damaged in doing so)

 

cheers,

Pete.

Edited February 1, 2008 by smileypete

[moggyjo]

Just for the record, engine running about 7 hours, was reading 14.3 turned engine off nearly a hour ago and now reading 12.4

[Tony Brooks]

Well done! That's very very helpful.

 

I would agree with Snibble and the others that it's most likely to be a poor connection somewhere between the domestic battery -/negative and the body of the alternator.

 

Also that the poor connection could be between the alternator itself and the bracket on the engine that it's bolted to.

So I would recommend testing for the above as follows.

 

Firstly run the domestic batteries down to 12.2v, which is very roughly half flat.

 

Then carefully scrape some paint (about 2p piece size) off the face of the alternator bracket that's between the engine and the alternator, using the end of a flat screwdriver, small scraper or something similar.

Start the engine and run at normal charging speed, then measure and write down:

 

1. The voltage across the domestic battery + and - terminals.

Carefully connect one end of the black jump lead to the alternator bracket where the paint has been scraped off, and carefully connect the other end of the lead to the alternator frame/body. Then measure and write down the following:

 

2. The voltage across the domestic battery + and - terminals (jump lead between bracket and alternator.)

Now, disconnect both ends of the black jump lead from the bracket/alternator.

 

Then carefully connect one end of the black jump lead to the negative/- side of the domestic batteries (that the thick black wires go to)

 

Then carefully connect the other end of the lead to the alternator frame/body, measure and write down the following:

 

3. The voltage across the domestic battery + and - terminals (jump lead between domestic battery negative and alternator body.)

Switch off the engine, first remove the end of the black jump lead from the alternator frame, then the other end from the negative/- battery terminal.

 

And that's it

I think the reason the clip on ammeter doesn't work so well near the alternator is because it works on magnetism and the alternator can create a magnetic field.

 

One other thing, I noticed there is a battery isolator on your instrument panel. When the switch is off, can you confirm it prevents the engine from starting at all?

 

(BTW never switch the battery isolator off while the engine is running unless there's an emergency! This is because the the alternator can get damaged in doing so)

 

cheers,

Pete.

 

 

Sorry not to plow through the posts, have we established the model of the alternator. If its a earlier ACR has anyone checked the idiot "earth"connection nut that secures the diode pack to the case? Usually found in a half moon cutout in the edge of the plastic cover. Good first check is to feel for warmth.

 

This may be way off the mark, but my experience shows it often gets missed.

[chris w]

Just for the record, engine running about 7 hours, was reading 14.3 turned engine off nearly a hour ago and now reading 12.4

 

As I asked earlier in this thread, what is the quoted accuracy of your voltmeter? If it's a 2% version, a reading of 12.4v means that your actual true voltage reading could be anywhere from 12.7v (100% charged) down to 12.2v (50% charged).

 

Hence your reading of 12.4v is meaningless without this info. If it's 12.7v then your batteries seem to be charging perfectly. If it's 12.4v or 12.2v after 7 hours, they're just nailed to the perch.

 

Borrow or buy a +/-0.5% accuracy multimeter and take the reading again.

 

Chris

[Keeping Up]

A great deal can often be interpreted from meters of lesser accuracy.

 

In this case, although Chris is absolutely correct in saying that it is not possible to tell the actual level of charge very accurately, it is at the same time significant that the battery voltage fell by 1.9 volts within an hour.

 

Whether this fall was from 14.5 to 12.6, or from 14.0 to 12.1, in either case it suggests to me that even when the charging problem has been located and cured, there is a strong probablity that the batteries themselves are no longer performing properly. Further tests (only slightly differnet) would need to be done to investigate this.

[smileypete]

Just for the record, engine running about 7 hours, was reading 14.3 turned engine off nearly a hour ago and now reading 12.4

 

OK, I think it would be best to pin down the problem with the wiring first.

 

The batteries may be undercharged and/or partly 'sulphated', but without the means to give them a decent charge it's hard to tell.

 

cheers,

Pete.

[Sir Nibble]

Nothing the indicator just flickeres from 0 to 25, with or without the jump leads, the volts on my solar panel regulator was reading 14.3 at the time I did this test,

Wendy

Belt slip by the sound of it.

[moggyjo]

Well done! That's very very helpful.

 

I would agree with Snibble and the others that it's most likely to be a poor connection somewhere between the domestic battery -/negative and the body of the alternator.

 

Also that the poor connection could be between the alternator itself and the bracket on the engine that it's bolted to.

So I would recommend testing for the above as follows.

 

Firstly run the domestic batteries down to 12.2v, which is very roughly half flat.

 

Then carefully scrape some paint (about 2p piece size) off the face of the alternator bracket that's between the engine and the alternator, using the end of a flat screwdriver, small scraper or something similar.

Start the engine and run at normal charging speed, then measure and write down:

 

1. The voltage across the domestic battery + and - terminals.

Carefully connect one end of the black jump lead to the alternator bracket where the paint has been scraped off, and carefully connect the other end of the lead to the alternator frame/body. Then measure and write down the following:

 

2. The voltage across the domestic battery + and - terminals (jump lead between bracket and alternator.)

Now, disconnect both ends of the black jump lead from the bracket/alternator.

 

Then carefully connect one end of the black jump lead to the negative/- side of the domestic batteries (that the thick black wires go to)

 

Then carefully connect the other end of the lead to the alternator frame/body, measure and write down the following:

 

3. The voltage across the domestic battery + and - terminals (jump lead between domestic battery negative and alternator body.)

Switch off the engine, first remove the end of the black jump lead from the alternator frame, then the other end from the negative/- battery terminal.

 

And that's it

I think the reason the clip on ammeter doesn't work so well near the alternator is because it works on magnetism and the alternator can create a magnetic field.

 

One other thing, I noticed there is a battery isolator on your instrument panel. When the switch is off, can you confirm it prevents the engine from starting at all?

 

(BTW never switch the battery isolator off while the engine is running unless there's an emergency! This is because the the alternator can get damaged in doing so)

 

cheers,

Pete.

Hiya Pete just done test tried earlier but could not get light to go out with wires on alternator anyway the results are,

batteries, 12.1,

After starting engine 12.45

voltage at battery with jump leads on alternator 12.24

voltag with one lead on battery other on alternator 00 ( freaked me out, sparks everywhere when attaching jump lead to alternator)

Tested batteries after disconnecting jump leads 12.55

Wendy

[Sir Nibble]

voltag with one lead on battery other on alternator 00 ( freaked me out, sparks everywhere when attaching jump lead to alternator)

Wendy

Cannot understand your zero volts reading, but that shower of sparks was probably your missing alternator output.

[Chris Pink]

Cannot understand your zero volts reading, but that shower of sparks was probably your missing alternator output.

 

Perhaps the wrong battery terminal? i do hope not.

[chris w]

I do feel that trying to get someone, totally untrained and unknowledgeable about electrics, to carry out complex (to them) instructions is very dangerous.

 

The fact that a shower of sparks resulted from one of these instructions would seem to imply that either the instruction was incorrect or the instruction was not clear or the tester simply didn't understand the instruction. Whatever happened, what would our reaction be if suddenly we got no more posts from the tester and later read on the news about a NB's blowing up.

 

I feel strongly that once instructions get past the basic, then either one of us with more knowledge should volunteer to attend the scene or we should tell the owner of the NB to bring in professional help. We shouldn't immerse the owner in a deeper and deeper labyrinth of instruction IMHO.

 

Chris

[Chris Pink]

one of us with more knowledge should volunteer to attend the scene

 

yes, i did, ages ago, it's not that far from me, got no reply.

Edited February 4, 2008 by Chris Pink

[smileypete]

Hiya Pete just done test tried earlier but could not get light to go out with wires on alternator anyway the results are,

batteries, 12.1,

After starting engine 12.45

voltage at battery with jump leads on alternator 12.24

voltag with one lead on battery other on alternator 00 ( freaked me out, sparks everywhere when attaching jump lead to alternator)

Tested batteries after disconnecting jump leads 12.55

Wendy

 

OK thanks very much that's quite useful to know.

 

The fact that something is getting through despite the alternator light being on, makes me think the light being on could well be another symptom of the problem with the battery charging.

 

 

A couple of things that would be worth doing to rule this out:

 

1. When the engine is off, are you able to twist the alternator fan and pulley by hand? Or is it held fast by the alternator belt? (You might want to use an old cloth to get a better grip and protect your hands).

 

 

If the answer to the 1. is no, then you could try the following

 

With the engine off carefully connect one end of the black jump lead to the negative/- terminal of the domestic batteries. Then connect the other end of the jump lead to the frame/body of the alternator. (There should be next to no sparks as the engine/alternator isn't running.)

 

2. Then start the engine, and give it a revv, does the alternator light go out?

 

 

If the answer to 2. is yes, measure and record the following:

 

3. The voltage across the domestic battery + and - terminals (jump lead between domestic battery negative and alternator body.)

 

 

Switch off the engine, first remove the end of the black jump lead from the alternator frame, then the other end from the domestic battery negative/- terminal.

 

 

Something else that would help is some digital camera pics of the thick black wires from the batteries to where ever you can trace them to. The pics you posted earlier were really useful to give an idea of what's there.

 

The tests you've done and pictures taken so far have been really helpful, and certainly rule out the batteries or split charge relay as being the problem.

 

cheers,

Pete.

[moggyjo]

OK thanks very much that's quite useful to know.

 

The fact that something is getting through despite the alternator light being on, makes me think the light being on could well be another symptom of the problem with the battery charging.

A couple of things that would be worth doing to rule this out:

 

1. When the engine is off, are you able to twist the alternator fan and pulley by hand? Or is it held fast by the alternator belt? (You might want to use an old cloth to get a better grip and protect your hands).

If the answer to the 1. is no, then you could try the following

 

With the engine off carefully connect one end of the black jump lead to the negative/- terminal of the domestic batteries. Then connect the other end of the jump lead to the frame/body of the alternator. (There should be next to no sparks as the engine/alternator isn't running.)

 

2. Then start the engine, and give it a revv, does the alternator light go out?

If the answer to 2. is yes, measure and record the following:

 

3. The voltage across the domestic battery + and - terminals (jump lead between domestic battery negative and alternator body.)

Switch off the engine, first remove the end of the black jump lead from the alternator frame, then the other end from the domestic battery negative/- terminal.

Something else that would help is some digital camera pics of the thick black wires from the batteries to where ever you can trace them to. The pics you posted earlier were really useful to give an idea of what's there.

 

The tests you've done and pictures taken so far have been really helpful, and certainly rule out the batteries or split charge relay as being the problem.

 

cheers,

Pete.

Hello Pete, when I did the tests the light had gone out,it just didn't go out when I first fired up the engine, it happened last week as well but only when touching the 2 terminals on the alternator still

Edited February 4, 2008 by moggyjo

[smileypete]

Hello Pete, when I did the tests the light had gone out,it just didn't go out when I first fired up the engine, it happened last week as well but only when touching the 2 terminals on the alternator still

 

Righto that's handy to know, taking that into consideration I've altered the tests I posted earlier slightly:

 

 

1. When the engine is off, are you able to twist the alternator fan and pulley by hand? Or is it held fast by the alternator belt? (You might want to use an old cloth to get a better grip and protect your hands).

 

 

If the answer to the 1. is no, then you could try the following

 

Use the domestic batteries until the voltage is about 12.2V

 

2. Start the engine, is the alternator light on?

 

 

If the answer to 2. is yes, try the following:

 

First carefully connect one end of the black jump lead to the negative/- terminal of the domestic batteries that the black wires go to. Then connect the other end of the jump lead to the frame/body of the alternator.

 

3. Does the alternator light go out?

 

 

If the answer to 3. is yes, measure and record the following:

 

3. The voltage across the domestic battery + and - terminals (jump lead between domestic battery negative and alternator body.)

 

Switch off the engine, first remove the end of the black jump lead from the alternator frame, then the other end from the domestic battery negative/- terminal.

 

 

4. Something else that would help is some digital camera pics of the thick black wires from the batteries to where ever you can trace them to. The pics you posted earlier were really useful to give an idea of what's there.

 

 

Sorry for all these tests, it looks like we're nearly there. If you can also post the pics mentioned above as well, it may be possible to identify the problem.

 

cheers,

Pete.

Edited February 5, 2008 by smileypete

[Sir Nibble]

1. When the engine is off, are you able to twist the alternator fan and pulley by hand?

This alternator has an internal fan, there's nothing to get hold of.

I do feel that trying to get someone, totally untrained and unknowledgeable about electrics, to carry out complex (to them) instructions is very dangerous.

 

The fact that a shower of sparks resulted from one of these instructions would seem to imply that either the instruction was incorrect or the instruction was not clear or the tester simply didn't understand the instruction. Whatever happened, what would our reaction be if suddenly we got no more posts from the tester and later read on the news about a NB's blowing up.

 

I feel strongly that once instructions get past the basic, then either one of us with more knowledge should volunteer to attend the scene or we should tell the owner of the NB to bring in . We shouldn't immerse the owner in a deeper and deeper labyrinth of instruction IMHO.

 

Chris

That's probably wise, but professional help is as likely as not to be a mechanic who is as good with electrics as I am with injection pumps!

yes, i did, ages ago, it's not that far from me, got no reply

Best plan.

[tomsk]

I do feel that trying to get someone, totally untrained and unknowledgeable about electrics, to carry out complex (to them) instructions is very dangerous.

 

The fact that a shower of sparks resulted from one of these instructions would seem to imply that either the instruction was incorrect or the instruction was not clear or the tester simply didn't understand the instruction. Whatever happened, what would our reaction be if suddenly we got no more posts from the tester and later read on the news about a NB's blowing up.

 

I feel strongly that once instructions get past the basic, then either one of us with more knowledge should volunteer to attend the scene or we should tell the owner of the NB to bring in professional help. We shouldn't immerse the owner in a deeper and deeper labyrinth of instruction IMHO.

 

Chris

 

You seem to have changed your tune Chris. Kudos to you.

[smileypete]

This alternator has an internal fan, there's nothing to get hold of.

 

Right, in that case try a spanner, adjustable spanner or something like that on the pulley nut.

 

If the pulley turns with moderate pressure, then the belt is likely to be too loose.

 

Or:

 

Grab the longest 'run' of the belt and see how far it can be pushed/pulled. May be a bit subjective for some people though.

 

cheers,

Pete.

Edited February 5, 2008 by smileypete

[NBMike]

I've just reread all the posts on this issue. Does anyone know if Moggyjo resolved her charging problems?

Mike