Any ideas ppls? Thinking it's ignition leads as battery is fully charged.

Thanks for your help.

I had this problem when the alternator belt was loose, check and see if it is slipping

Thanks PP. Tension is kosher :(

Any ideas ppls? Thinking it's ignition leads as battery is fully charged.

Thanks for your help.

Nothing to do with ignition leads! More likely the belt is glazed and slipping, or the brushes in the alternator are worn and not making good contact with the slip rings. How many Km on the car?

Sounds like regulator brushes. You can usually hear a slipping belt.

Sounds like you need to get the alternator checked, see if it's delivering correct charge across the rev range.

I agree that the most likely cause is worn brushes. If you can use a screw driver you can probably replace the brush/regulator pack on your alternator. 98% of the time this is all that goes wrong with your alternator, and it will cost you less than the service fee for an auto electrician to look at it. Take the old one out and take it down to your auto electrician. A new brush pack for a Bosh alternator is usually about $50. They can be a little tricky to put back in as you need to get the brushes into place, but a little fiddling and not too much forcing should get you there.

Man $50!! I got mine for $12 from the local autoelec, for the field coil . i also had the sparky put the Armature on the lathe and skim the crap that had melted to it. but yeah on my old trooper the battery light would come on at about 2000rpm, on testing it was charging just enough at idle but as revs rose and load increased it dropped off. same prob, brushes.

Put a voltmeter on the battery and run the engine up to about 3000 rpm.

If it goes above 14.4V yur alternator is overcharging.

The battery will be charged ok (and will get fried) but the light will come on.

Thanks for the help fellas.

Ol' Fart you could be on to something. At idle it sits around 14.4 / 14.5 but peaks at 15.5. Can't be precise (just me here) but it sounds like it's at about 3000 rpm when the voltage climbs. The light only comes on around 5000+ rpm though :/

Two points:
14.4 volts is the normal charging voltage, should not go higher. 15.5 means your brushes are making poor contact, or the regulator is stuffed. It normally uses battery voltage as a reference to regulate alternator output voltage and current.

5000 rpm is too high for such an old engine! Alternator is doing about 12,000 rpm, brushes are having trouble staying in contact with the armature.

Rip it out, get it checked. Simple!

K will do ty

over charging can also be caused by an internal fault (shorting cell) in the battery... i would load test the battery before ripping the alternator out

Regulator stuffed. All good now :p