Alternater trouble - HELP !!

Help needed please from anyone who knows about alternaters and their wiring.

We have checked the alternater on the mini and it worked, but once on the scamp it does not. Have checked the wiring and it is correct to the Haynes manual. Just cant seem to get any charge out of it.

If anyone can help please get in touch as we are getting DESPERATE !!!

Many thanks in advance (hopefully!)

Colin

Is the alternator warning light coming on? This might not seem important, but the current through it is used to "prime" the alternator's magnetic field on startup. At least, it is on mine.

On the alternator you should have 2 wires,the heavy brown one that is connected directly to the battery and the smaller brown and yellow one that goes to the warning lamp.First check the main feed to the battery if that is o.k. then remove the small lead,switch the ignition on and short it to a good known earth and the warning lamp should come on(the alternator light has a 12 volt feed going to it and is earthed through the windings of the alternator and when the alternator is running it should put the equivalent voltage to the other side of the bulb and cancel the light out).If you have got both of these then reconnect the alternator,start the engine and check the charge rate at the alternator(should be between 13.6 and 14.5 volts with a good battery on fast idle),if that is o.k then check it again at the battery and it should read about the same.Now give it some load(i.e switch the heater on,the lights hazard flashers etc.)and on fast idlle(about 1200 -1500 rpm to make sure the cut out is working)it should be charging between 12.8 and 13.5 volts.
Hope this is of some help.

Thank you so much for your help Chris. With your help we have managed to suss it out