Mondeo TDDI is it battery or alternator?

[smileymikey]

I have a friend who is having problems starting his Mondeo, which to be honest doesn't get used a great deal. If he charges the battery it will fire the car up eight or nine times then runs out of juice. There are no charging lights coming up on the dashboard, and when he puts a multimeter on it he isn't getting any kind of sensible volts. I've promised to help him out changing the alternator, but having had a similar situation with my Chrysler which turned out to be a snafu'd battery I don't want him to waste his money or time....any pointers to clarify which bit is causing the problem?

[anonymous-user]

What voltage is he seeing when the car is running at idle?

[smileymikey]

Apparently its 12 at tick over rising to about thirteen under revs

[anonymous-user]

Sounds about right to me. How long are the journeys after a full recharge? What frequency? If they are only using it once every 3 months to go to the corner shop that won't be the alternator!

[NHK244V]

should be over 13 at idle and around 14 at revs, IF it has the ecu controled alt (smart charge) there are inherant problems with that setup differant to a normal alt but with 12 at idle i'd say the alt is goosed, a battery should show 12 to 13 by itself.