generator lights still wont go off.HELP!!

[dubbedup67]

some f you may have seen my last thread about the problems ive been having with my charging system

if not heres the run down

was out driving my 68 a few nights back when i could smell burning electrics,then a few seconds later the generator light came on.
pulled over turned everything off, and no burnt wires,blown fuses or anything.
drove almost 15miles home with no problems,if anything she ran a bit better.weirdly.

thinking it could be my regulator that was the problm i bought and fitted a new one today.
fired her up and the generator light is still on.
again checked all wires and fuses and everything is ok,battery is good measuring just over 12v.
started her up again and did the multimeter test with her running and im only getting the same off the battery as i was when it wasnt running,telling me she isnt charging.

however,i took her for a spin round the block,all lights on wipers the works,got home and turned it all off again,started her up and boom no problems but the generator light is STILL on and the multimeter still says only just over 12v when running?

surely me starting and stopping her and running her around the block with everything on would have flattened the battery right?

what am i missing here,s is the dynamo thats has it?
why did i smell burning electrics if there arent any?

can someone please help me out because im completely stumped.



cheers matt

 

[RICH-I-AM]

Stick the multi meter on and take a reading.
Get someone to start it.
Read the multimeter whilst cranking and then when its running.
Leave it running for 2 mins.
Then get your helper to switch lights ect on.
You should be able to see by your readings if the dynamo is ok.

Rich

 

[dubbedup67]

Stick the multi meter on and take a reading.
Get someone to start it.
Read the multimeter whilst cranking and then when its running.
Leave it running for 2 mins.
Then get your helper to switch lights ect on.
You should be able to see by your readings if the dynamo is ok.

Rich

Thanks man il try that.

What's worrying is the burning wire/electrics smell.
There's no evidence of burnt wires or anything so I don't know why I would have got that.??

 

[Dave.P]

Could try checking the dynamo brushes, in case they're worn out ?

 

[dubbedup67]

Could try checking the dynamo brushes, in case they're worn out ?

Would worn out bushes cause the burning smell?
And how easy are they to replace?

 

[krusty]

If you multimeter isn't going up when you start the engine then either generator is not working or you cable connections are damaged, you should clearly see the multimeter jump up a bit when you start the engine.
I would check your wiring, if that's ok I would say its time to change the generator or treat yourself and upgrade to a alternator.

 

[Stevec]

Have you checked the wire from the ignition to the generator this is what gets it going? I had the same problem and changed my alternator but then found out it was the actual wire which was burnt out.

 

[Dave.P]

Could try checking the dynamo brushes, in case they're worn out ?

Would worn out bushes cause the burning smell?
And how easy are they to replace?

Don't remember a smell when mine went, but who knows??
I did it years ago when I knew nothing so can't be that hard, I probably used the Haynes manual. You don't have to take the dynamo off they just slide out of the slot in it, held in by a clip iirc
Your wiring could be melted too somewhere, so two things to check.
There's always something eh !

 

[89Rallye]

Brushes will definitely cause a burning smell as they start arc'ing on the commutator.

As stated, try checking the wire front to back that feeds the dash without this feed the dynamo won't turn on. Try belling it out with your multimeter set to continuity.

 

[dubbedup67]

Brushes will definitely cause a burning smell as they start arc'ing on the commutator.

As stated, try checking the wire front to back that feeds the dash without this feed the dynamo won't turn on. Try belling it out with your multimeter set to continuity.

Are you meaning the blue wire or the big red wire.

 

[Stevec]

The blue wire

 

[89Rallye]

Yes blue one will come out behind the clocks (ignition light) alternatively you could flash it to the +ve on the battery to see if it switches (excites) the dynamo on but wouldn't really recommend it if your not 100% sure what your doing.

 

[dubbedup67]

Yes blue one will come out behind the clocks (ignition light) alternatively you could flash it to the +ve on the battery to see if it switches (excites) the dynamo on but wouldn't really recommend it if your not 100% sure what your doing.

ive checked the blue wire behind the dash.
and at the engine end where it connects to the terminal on the reg.both those bits seem fine,is there a way of looking underneath the van? does it run through any chassis section?
quick question though if it was this wire surely the light wouldnt be on as if this wire is faulty there'd be no power?

 

[89Rallye]

Yes blue one will come out behind the clocks (ignition light) alternatively you could flash it to the +ve on the battery to see if it switches (excites) the dynamo on but wouldn't really recommend it if your not 100% sure what your doing.

ive checked the blue wire behind the dash.
and at the engine end where it connects to the terminal on the reg.both those bits seem fine,is there a way of looking underneath the van? does it run through any chassis section?
quick question though if it was this wire surely the light wouldnt be on as if this wire is faulty there'd be no power?

It's complicated as the light works back to front, the power is fed from the other side to the alternator/dynamo (from the ignition). With the ignition on the dynamo gives a negative feed to the light (hence it's illuminates) then when it starts spinning it gives out a positive feed which then turns off the light.

You won't really see the cables under the van as it's all sheaved and the majority is in the chassis section, really though there's no point doing a visual inspection all you have to do is a continuity test with a basic multi meter to make sure the cable is ok. When you do this, do it with the cable disconnected at both ends just in case the fault is feeding from elsewhere.

 

[dubbedup67]

Yes blue one will come out behind the clocks (ignition light) alternatively you could flash it to the +ve on the battery to see if it switches (excites) the dynamo on but wouldn't really recommend it if your not 100% sure what your doing.

ive checked the blue wire behind the dash.
and at the engine end where it connects to the terminal on the reg.both those bits seem fine,is there a way of looking underneath the van? does it run through any chassis section?
quick question though if it was this wire surely the light wouldnt be on as if this wire is faulty there'd be no power?

It's complicated as the light works back to front, the power is fed from the other side to the alternator/dynamo (from the ignition). With the ignition on the dynamo gives a negative feed to the light (hence it's illuminates) then when it starts spinning it gives out a positive feed which then turns off the light.

You won't really see the cables under the van as it's all sheaved and the majority is in the chassis section, really though there's no point doing a visual inspection all you have to do is a continuity test with a basic multi meter to make sure the cable is ok. When you do this, do it with the cable disconnected at both ends just in case the fault is feeding from elsewhere.

Ah ah I'm with ya.

Quick but probably stupid question.
How do I do a continuity test at each end of the wire when one end is in the engine bay and the other behind the dash?

Matt

 

[89Rallye]

Ah ah I'm with ya.

Quick but probably stupid question.
How do I do a continuity test at each end of the wire when one end is in the engine bay and the other behind the dash?

Matt

Get yourself a separate length of wire

 

[dubbedup67]

Ah ah I'm with ya.

Quick but probably stupid question.
How do I do a continuity test at each end of the wire when one end is in the engine bay and the other behind the dash?

Matt

Get yourself a separate length of wire

Ah and attach the new bit of wire to one end and run it to the other so I've got the two ends together to test yeah?

 

[89Rallye]

Ah ah I'm with ya.

Quick but probably stupid question.
How do I do a continuity test at each end of the wire when one end is in the engine bay and the other behind the dash?

Matt

Get yourself a separate length of wire

Ah and attach the new bit of wire to one end and run it to the other so I've got the two ends together to test yeah?

Bingo..

 

[dazza1975]

connect one end to the body work to earth it out and then on the other end put the multi read on the cable and touch the body with the 2nd prong on the reader

 

[Skyguy]

If you are running a dynamo then I would check the brown wire at the back of the dynamo and if this is burnt then you need to check your earth connections. The dynamo does not work in the same way as an alternator in such that it does not need the light to excite it.