Alternator problems

[Siggy]

3.2 Carrera

Ignition light not working.
Bulb OK
Remove alternator.

I have 12 volt to the main feed
A good earth
Earth the blue warning light wire and it lights.

I have just replaced the alternator and its exactly the same, is it me having a blond moment, or a duff new alt?

[ExAudiSi]

Isn't the blue wire supposed to have a 12v supply on it when the igntion is switched on?

Not sure as I've not come across a problem like this before, so haven't needed to check what was on the wires to the alternator.

[Siggy]

It should have 12v from the ignition switch, but it earth's through the alternator, which turns the light on

Then when the alternator starts charging 12 volt from the alternator which turns the light off, it counter acts the 12v from the ign

[zola1]

The alternator circuit is exactly as you described (so long as your alternator has an internal regulator), its appears you have a duff new alternator. Is it a recon or a Bosch new one.

cheers

[Siggy]

It has an internal reg and its a recon, but from a good supplier

Dave

[tr7v8]

It has an internal reg and its a recon, but from a good supplier

Dave

It needs checking over as it sounds like it is duff.

[zola1]

I agree with Jim, it needs going on a altr rig to test it (w/lamp is through the rectifier pack sounds like a diode has failed).

cheers

[Siggy]

That was my thoughts, just trying to convince myself that ist was a duff unit, especially as its the same problem as the original unit

[Siggy]

I rang RPM, who supplied the new alternator and Nick told me to take it to them and they would check it out.

He Just rang to say it was the new unit that was faulty, they have changed it and are not charging me for thier labour