alternator not charging battery.. charge lht does not come on when ign on before motor starts.(and stays off when motor running) does this mean the alternator is stuft or just not getting excited ?
if you have a voltmeter test the battery while the engines running. should be putting out 13-14 volts. if not alternator stuffed.
turn on lights when engine running, rev engine, if lights brighten when revs up then battery is stuffed.
also, is the charge light on but very dim as opposed to not lit.????? that's a sign of alternator stuffed.
could be the brush assmebly
either way. if the alternator is stuffed most likely the battery will be soon also.
no i am not an autoelec. am son of one. could have also embarrassed said father with my above diagnostics.
definately no charge to batt. no charge light at all, ever.( not dim). If the alternator is faulty wouldnt the charge light still come on and stay on ???
The charge light gets power from the battery, and is usually grounded by the alternator to make it come on. If the small connector to the alternator has fallen off then on some cars you get this effect (no charge, and no alternator light).
The alternator light really only tells you if the belt comes off and it's not spinning. There are a couple of scenarios where the light won't come on and the alternator isn't charging.
To diagnose you'll definitely need a multimeter, check the battery volts to start with. If it's below 13V when running then check the fat battery connection on the alternator.
If that's 14V then you've got a bad connection on that big fat charge wire.
If it's below 13V as well then you need to check the other two wires that go through a connector into the alternator (battery sense, and charge light, assuming you have an on-board regulator, if the regulator is off-board then you'll have different wires going through the connector).
Plenty of diagnostics on the web, have a bit of a dig and you'll sort it out.
i remember a dark and stormy night when nebbian rescued me from roadside electrical troubles. 
First thing I did was test it with a multimeter. 12.2 volts with motor running. 12.6 with motor off !!! what I'm up in the air about is this exciter circuit(ign light) thingo.
Why doesnt it (the light)come on when key turned to ign (all other warning lights on). motor is not running at this point so does alternator output make any difference.????
Great weekend though.
Great weekend though.
Prob a bit late now and type of hot rod would help, but I'd take a guess it's the brushes in the alt. Just pull it off and have a gander, if brushes are too short with burn/arc marks on the slip rings (the bits the brushes run on) then that's it, change the bearings at the same time 
