Club 80-90 Forums

Hi.

My Dad has just replaced brushes and electrode on my alternator as it had stopped charging. The alternator is definitely working now, but it's not charging the battery.

On inspection it seems there is a wire that should be going somewhere but isn't, it's the output apparently. Does anyone know where this goes or a wiring diagram for it please?

Many thanks,
Andy

Should have said it's a 1988 VW T25 1.9 petrol DG.

Thank you.
Andy

I think you had better put up a pic so that we can see exactly what you have there otherwise we will have to ask numerous questions to build up a mental picture.

Thank you. The van is at my parent's house but will go there tomorrow morning and get a pic.

Andy

Late dg has a red wire from alt to the starter ( which in turn joins to the batt) and another red to the black box both from an m8 ring terminal on the alt.
There is also a small blue wire which is the charge light, it goes via the black box and fuse box to the dash, without it the alternator won't produce the approx 14v
What volts do you have with engine running on the alt main terminal and on batt?
If you dont get the approx 14v try revving the engine to 3k revs and see if it starts making the voltage?

I was trying to avoid the guessing games!

Oldiebut goodie wrote:I was trying to avoid the guessing games!

back to your old self then

We all know that there are numerous previous bodges in the last 20+ years so telling a 'new to him' van owner to put the red/black/whatever wire to y point could lead to disaster which I was trying to avoid. I know that some wires in my engine bay don't correspond to the original vw colours like a lot of others.

As Itchyfeet says, on some years, that wire goes over into the black box on the left in engine bay, then on to starter.

http://wiki.club8090.co.uk/index.php/VW ... ain_cables" onclick="window.open(this.href);return false;

Thank you very much. Going to pass this info on to my Dad and go and have a look myself. Fingers crossed we can get the old girl going again

Andy

Guys, please can you help again?

This is all a bit above my head, but my Dad would like to know where does the red cable go after the black box? Apparently this is somehow drawing 30amps! If we can find out where it goes after the black box maybe we can fix the problem.

Thank you.
Andy

It should go to the battery. Do you mean it is drawing 30A with the engine running or without? With the engine running it will be the normal charging from the alternator to a somewhat discharged battery or some other high current drain. Without the engine running - something or several things are switched on taking high current.

In my 88 DG pic above and below the smaller red from alt to the black box is used to power the engine manifold and carb heaters only via a relay, it does not connect from the black box to the starter or battery. Try pulling the relay out of the socket in the black box.

The second larger red from the alt goes to the starter motor.

As said your wiring may have been changed over the years so pictures will say a lot.

There is loads of space around these engines, just follow the wires between alt black box and starter.

These cables are not fused and connect even when engine is off so if you have concern about a short or heavy current draw disconnect the battery when you leave it, you don't want a fire.

That's the trouble - no one can be sure without seeing. I doubt that there are many vans with completely original wiring. 30A draw is one heck of a lot if the engine isn't running!

I haven't been able to get round there today. 30amps draw when running I believe.

Will catch up with my Dad tomorrow and see where we're at and take photos too.

Thanks very much for all of your help, I really appreciate it.

Andy