What is D+

[Sam]

I spoke to someone at the factory who told me to connect the 2 large brown wires to the D+ connection on my alternator. Is this right? If so where does the other smaller wire go? I had it connected but the ignition light stayed on constantly.

Does anyone know how to wire up the WF supplied alternator?

ps I have searched and i have read but am still a little unsure.

[Peter M]

If its the standard zetec alt then the terminal nearest block is where the thick brown wire goes and the middle terminal which is marked D+ is where the brown/yellow cable goes the outside terminal is not used.

[Sam]

So the guy at the factory (not Mark) was wrong.....Because i cautiously tested the way you suggest and it seems to work. I was usure whether to go against what the factory said......But if that is the way to do it then....Thanks alot.

[Sam]

How can i test that the alternator is working as it should?

[Peter M]

Check ignition light is lit when ignition on and goes out on starting ,you may have to rev engine slightly for light to go out.With a voltmeter/multimeter with engine running and ign warning light out you should have about 14 volts across battery, if so then alternator should be charging.

Why do you think your alternators not charging.

[Sam]

I havent had it connected in properly yet, i would just like to know that it is......

Cheers for your help Peter.

[Sam]

Right i have plugged it in both ways that have been suggested. The ignition light comes on and the alternator seems to be charging the battery but the ignition light doesnt go off. I have tried the ignition light lead on both of the other terminals with no success. Any ideas?

[Peter M]

With the brown/yellow wire disconected from alternator with ign on, is the ign warning light lit .

[Sam]

Yes

[Peter M]

OK with the brown/yellow disconnected and not touching earth then the light should not be lit.

What you need to do now is on the terminals of the ign warning light there are 2 wires,check that one is green thats the +ve the other should be the brown/yellow, alternator field wire..

[Sam]

Yes that is how it is wired.

[Peter M]

The ignition warning should not be lit with the brown/yellow wire disconnected this goes to earth via the alternator.You could it seems have a short to earth with this wire.If you have a multimeter with this wire disconnected at the ign lamp and alternator see if you can measure a short to earth with this wire.

[Sam]

Ok Peter, I will have a look.

Thanks again for your help.

[Blatman]

Try earthing the body of the alternator. You can do it temporarilly as a test with a jump lead. If the ignition light behaves as it should then that's problem solved.

As a further test, with the engine running switch *everything* on. You should still see well above 12 volts, and with a little throttle (2000rpm) you should be back up to 14 volts. If you can't get 14 volts with everything on and a few revs, then there is a chance the alternator is not working properly. Watch the meter as you switch stuff off too. A spike of over 14.4 volts suggests the regulator (part of the alternator also sometimes called the diode pack) is suspect.

You also need to test the battery. Leave it overnight, then test it before switching the car on. Anything less than about 12.5 volts would suggest the battery is not as healthy as it might be.

[Sam]

Spoke to WF this morning and they suggested a bad earth. I have just been out and tested it with a multimetre and there is no resistance between the alternator body and my chassis earthing point suggesting a good earth.

Any other ideas?

P.s Blatman where would the regulator be? I never had one supplied.