Kit car but based on a 1989 136 Rapid

The alternator was only charging at 13.2V I had it refurbe, he claimed there was nothing wrong, it had been stood at least 5 years, but put new bearings & brushes in & evacuated all the dead spiders.

Putting it back on it's still only charging at 13.2V, also there is a 250mA drain on the battery when everything is switched off, if I remove the yellow wire that drops to 3mA drain.

SOmebody has suggested that a diode has failed inside the alternator, I will take it back in the new year but wondered if anybody had any tests I can do to prove it, I did find one using a multimeter & going from the blue wire to ground & then yellow wire to ground with the multimeter in diode mode, but can't find it again.

Hi, welcome.

Quick Google search gave this for general stuff - https://www.youtube.com/watch?v=WZ3yMv0O70I

For general principles (on Lucas but principles remain) (part one) - https://www.youtube.com/watch?v=lPmk2FXs_18

Part Two - https://www.youtube.com/watch?v=TMgRfToSiLY

HTH.

42 minutes ago, nta16 said:

Hi, welcome.

Quick Google search gave this for general stuff - https://www.youtube.com/watch?v=WZ3yMv0O70I

For general principles (on Lucas but principles remain) (part one) - https://www.youtube.com/watch?v=lPmk2FXs_18

Part Two - https://www.youtube.com/watch?v=TMgRfToSiLY

HTH.

Thank you unfortunately all of those relate to a Alternator/Regulator, not an Alternator with a separate Regulator,

Sorry, wouldn't the principles still apply, I don't know much about German ideas and ways of doing things though I do remember the original VW Beetles were 6v (well, IIRC that is).

1989 136 stays into the Favorit so as it's also busier there you might be better asking there (assuming, always dangerous, that the alternator with separate regulator was in that model). - Skoda Favorit, Skoda Felicia, Skoda Fun and Skoda Forman - https://www.briskoda.net/forums/forum/90-skoda-favorit-skoda-felicia-skoda-fun-and-skoda-forman/