Alternator drain problem

[familyogre]

Hi There

First time post, hope someone can gove me some advice.

essentially i've a battery drain on my 92 pajero.

it was fine then something has gone wrong somewhere and i need to know if it's alternator or a short/bad earth.

essentially with the alternator disconnected i get 0.01 amps with everything off, car runs fine, everything words etc. If i connect the alternator it's going over 20amps when i place the ammetre in series between the negative terminal and the battery post. In fact if i connect the negative battery terminal to the engine block itself it's drawing the same current.

Has something gone badly wrong or has an earth dislodged, wire crossed and so on.

I've only had the car a short time and the wiring is pretty iffy to say the least.

Anyway, some help would be appreciated

Cheers
Familyo.

[PBBIZ2]

What exactly do you mean by 'when I disconnect the alternator the car runs fine?'. Are you disconnecting the positive or the negative? I suspect disconnecting the negative wire will do nothing as the alternator probably is earthed via the mount bracket.

Maybe 'Scott' can help?

[familyogre]

Thanks for the reply

by disconnecting i mean completely disconnected. I pulled the plug at the back of the alternator and the 2 other connecting wires as i wanted to check all the wiring and connections.

With that all disconnected the car starts fine and runs well (off a full charged battery).

[-Scott-]

Maybe 'Scott' can help?

Well, thanks for the vote of confidence, but I would've thought you know alternators better than I do.

First thought is a dodgy regulator? If it has an internal fault it could be effectively connecting the battery sense line to ground?

I suppose faulty diodes could also explain the symptoms?

Try disconnecting only one wire at a time, to see if it narrows down to one circuit.

[familyogre]

have fiddled about and the drain is down to 2.3 amps, one of the wires was shorting onto the case.

when i've got the alternator connected (and drawing 2.3amps) i dont get any ignition/battery lights, but if i disconnect the main wire to the alt i get all the ignition lights.