Diagnostic Port Voltage, Xantia II

addo · Unread post by **addo** » 08 Mar 2010, 21:44

I'm still battling an erratic running condition (low power at times, and stumbles/misfires under light throttle). Plugging in the generic tool yesterday gave voltage fluctuating readings between 12.4 and 13.2 (hot idle).

A mate suggested that it's reading a more regulated ECU supply voltage - not the actual charging voltage. Is this correct?

Car is at 100K miles now; wondering if the alternator is perhaps wearing (brushes) or diode breakdown occurring. No discernable noises.

Cheers for any suggestions!

wheeler · Unread post by **wheeler** » 09 Mar 2010, 14:30

The power at the diag socket is the same as you get at the battery, its not a special regulated supply.
Have you checked the voltage with a proper multimeter to see if its any different, i wouldnt take the reading off the diag tools built in meter as gospel.

addo · Unread post by **addo** » 09 Mar 2010, 22:18

Thanks; I haven't cross-checked its charge voltage yet, but will today.

What kind of mileages do UK owners get out of a Xantia alternator?

Regards, Adam