vw beetle not charging

[Rattybadger]

this beetle is ok one minute and not charging the other , i whent out for ride all day the charging system on dynamo was ok it was puting out charge i went over to see a friend and when came out the bloody thing would not start? it has new dynamo brushes are ok all wiring ok fuses same and earths been checked i have no idea and i have checked the battery????? any idea's

 

[Burnerman]

There's a good chance the fault is in the control box - the black thing with the terminals A1, A, F,D,E.
This regulates the output voltage to suit the battery - do you have a replacement unit?
For the life of me, I can't remember how to test them but if you can get the outer cover off, rub some glass paper between the relay contacts.
This is one application when an ammeter is a useful addition!
In any case, test the output with a meter across the battery terminals....look for something over 13.5v.
John

 

[Mursal]

12Volt or 6, we'll stay with the 12volt system for now

As above, think from memory they use a small 2 bobbin regulator? And its external from the dynamo.
How do you know when its charging? Don't depend on the warning light for fault finding as its controlled by a set of contacts in the regulator (I think).

Think you jump the DF (dynamo field) wire to + 12 volts and if it start charging you know the dynamo is working. Then its down to wiring or regulator. Some of those had a bad ignition switch, but I think you will find the charging light goes dim when it should go off.


Links
http://www.vw-resource.com/generator.html#charging

 

[Rattybadger]

12Volt or 6, we'll stay with the 12volt system for now

As above, think from memory they use a small 2 bobbin regulator? And its external from the dynamo.
How do you know when its charging? Don't depend on the warning light for fault finding as its controlled by a set of contacts in the regulator (I think).

Think you jump the DF (dynamo field) wire to + 12 volts and if it start charging you know the dynamo is working. Then its down to wiring or regulator. Some of those had a bad ignition switch, but I think you will find the charging light goes dim when it should go off.

it is 12v i have a volt gauge fitted in tank to tell me voltage .the only thing i can think of is the speedo whent wrong and the earth system is connected below clock ,i have reconnected earth though so this should not be problem.
Links
http://www.vw-resource.com/generator.html#charging[/QUOTE]

 

[Peter.N.]

You can check if its the regulator that's faulty by holding the regulator armature away from the core, either with your finger nail or by sliding something between them, this will keep the contacts closed so that it doesn't regulate, it should then give you full output, if it drops below normal when you let go of it the contacts probably need cleaning as John says.

On the Lucas regulators the regulator coil is the left hand one looking from the front with the terminals at the bottom. This is for the black bakalite regulator, there is a metal cased one with three coils.

If I remember rightly the open circuit voltage should be about 16 volts with it disconnected from the battery, you can do this by inserting a piece of card between the cut out contacts (the right hand coil).

Peter

 

[Jackrae]

Just be careful if you're going to play with the regulator. If you accidentally close the contact on the low voltage cut-out (that's the one with the open contact) it will lock in and drive the dynamo as a motor so discharging your battery. The only way to release it is to disconnect the battery.

Do not fiddle with any of the adjusting screws. If you do then you will have ruined any calibration set-up.

Cleaning the contacts with extremely fine emery is about the only maintenance an DIYer can do.

 

[Burnerman]

Just be careful if you're going to play with the regulator. If you accidentally close the contact on the low voltage cut-out (that's the one with the open contact) it will lock in and drive the dynamo as a motor so discharging your battery. The only way to release it is to disconnect the battery.

Do not fiddle with any of the adjusting screws. If you do then you will have ruined any calibration set-up.

Cleaning the contacts with extremely fine emery is about the only maintenance an DIYer can do.

Aye, I remember doing that on my first motor....1960 mini minor
John