Alternator pushing out a steady 2.4 v - Why !!???

[devout gooner]

Well the title pretty much says it all. I wonder if any of you guys can explain to a dullard like me, why the alternator on my Peugeot xud9a van engine is only producing 2.4v, and is it a case of just replacing the whole unit. thanks in advance , Rob.

[Steve_D]

How are you measuring the 2.4volts?

You should be measuring the alternator output with it connected to the rest of the system so should be seeing at least 12.something volts of the battery.

If you are trying to measure an alternator without it connected then you will get next to nothing because the alternator needs a 12volt stimulus on the wire to the charge light before it will start to charge.

Steve

[annodomini2]

If you measure the voltage across the battery with the engine running, it should read around 14.5v.

With a fully charged battery and the engine stopped it should read around 12.5v

[devout gooner]

I disconnected the two main cables, but left the thin charging light wire connected for that reason ,won't that work ?