help??

If I decipher your message correctly (and I'm not sure I do) you are getting a lower reading with the engine running although the difference of 20mV is negligible. Looks like your alternator is not charging. Could be brushes, rectifier, broken fan belt, faulty feed to the field coil.

Of course knowing the car may help a bit too.

Sorry its a pug 405 deisel.i have no batt light when i turn the key so i am thinking big money for new alternator,??

start the engine ,switch on lights ,H.R.screen, etc and report the reading from your meter, Thanks Fitzy

If you are the Chris in Addlestone, you could get Roy Auto Electrics in Hetherington Road, Shepperton (01932 770136) to look at it. I have found them very good in the past.

I have spoke to then today. and they have told me to bring it over to them and they can rebuild it for me, but in the meantime i went out last night and sprayed it all with WD40 started it ok first thing and have got volt meter on it and it has been 13.5 volts all the time i am driving,drops to 13.0 volts when sitting at lights etc.like they said keep a eye on it .. once again thanks for the replys..chris.