Yeh cheers fellas self regulating is definetely the way to go, saves hassles.

Thanks for your help

For details on swapping alternators, see Alternator, Upgrades

sparkyza is right, an internally regulated alternator would definately be the better option. First thing I do with a new datto is replace teh alternator with a new 70 amp Leece Neville universal alternator (retails about $180). If you're in brissie, PM me and I'll sort you out trade price.

I'm not sure what you mean by 'L shaped' clip, if it is teh main battery positive wire the rectifier is probably knackered, if it is teh 2/ 3 pin connection, the reg is probably knackered. either way, if you've got a int reg alt lying around, fit it up. Depending on brand/ type, you will need to locate the warning lamp and possibly ignition wires at teh regulator and extend to the alt.

That is the field i was talking about.I would have gone for the build in reg. type alt from the start,much easer to wire and more reliable!

dingdang,

Havn't been able get hold of an ammeter yet to suss out what is causing the problem. I think the regulator could be bustedl, when the car is at idle you can hear the alt. coming on and going off pretty frequently.

When I stop the car, turn the ignition completely off, and remove the L shaped clip from the alternator, there is a large spark. If i leave it off, the battery doesnt drain.......

I have a self regulating alternator that I am pretty sure will fit.

I'll whack it on tomorrow and see if it makes any difference.

it could also be that the current draw discharging your battery is un related to your alt probs. using an ammeter between the battery positive post and terminal, check teh actual current draw with everything off and all doors closed. if it exceeds 0.05 amps, it will flatten a battery overnight. keeping the ammeter in place, pull fuses/ disconnect consumers until the draw goes away. this will tell you which circuit/ consumer is drawing and allow you to diagnose the fault. if no excessive draw is shown (<0.05A), the problem may be with the batteries, (I know that you said one was 'good', but sometimes even brand new parts fail). maybe at that point it may be time to see your local auto elec. if he/ she is ok with it, they may even let you watch while they sort it out, valuable for next time!

That can also be due to faulty wiring,somehow the field point on the alt. is getting a 12v supply witch will draw 2-4amps.
I think if you sort the wiring your troubles maybe over!

Dingdang, cheers mate that helps a lot.
Hopefully I'll get a chance to fix it sometime these next couple of days, I'll rewire those wires mentioned in your post as the old wires are getting a bit dodgy and corroded anyway.

I also should have mentioned that somehow the battery is getting drained flat (maybe a short?) I have tried another battery that I know is good, same problems, and it too was dead flat the next morning.

Cheers for the feedback

I think Dinggang is spot on!

The alt warning light is earthed via the external regulator, not the alternator. The alternator drives the regulator warning lamp circuit via the neutral {star point) connection within the alternator stator windings. The lamp coming on and the headlights becoming brighter at the same time usually indicates a faulty wiring connection between the neutral output at the alt and the reg. at this point, the reg thinks teh alternator is not charging, increasing field current and thereby increasing the charge voltage to compensate, while at the same time bringing on the warning lamp. Check/ rewire the 3 wires between the alt and reg and your problem should clear up.