i have a 03 v8 4.4 rangerover, new alternator fitted but still no battery light on the dash whether the engine is running or not! no charging voltage over the battery with a multimeter, when shes runnign no idea??

a jones, November 2009

Alternator wont work if bulb is blown. Replace bulb.
Pity you didn't ask before spending all that money on a new alternator.

griff, November 2009

if you earth-out small wire from alternator [poss marked "wl"] the warning light should illuminate,if not then trace wire back to loom/connectors to check if broken. by the way if ign bulb has blown alternator wont charge -so its worth checking bulb to see if its ok.

k, November 2009

I have no particular or specialist knowledge here but wikipedia says this...

"Once the engine is running and the alternator is generating, a diode feeds the field current from the alternator main output, thus equalizing the voltage across the warning light which goes out. The wire supplying the field current is often referred to as the "exciter" wire.

The drawback of this arrangement is that

if the warning light fails or the "exciter" wire is disconnected,

no excitation current reaches the alternator field windings and so the alternator, due to low residual magnetism in the rotor will not generate any power.

However, some alternators will self-excite when the engine is revved to a certain speed. The driver may check for a faulty exciter-circuit by ensuring that the warning light is glowing with the engine stopped."

Your vehicle may be different...

Peccavi, November 2009

this is just a thought does your alternator have a SEPARATE REGULATOR ? (test this for output) if not
go back to where you had the alternator from ,you could have had a duff one not all manufactures re test on rebuilding .

wirecutterman, November 2009