Odd electrical fault

[totta Crolla]

The battery light does not come on at all but the car starts ok, the battery light does work, I have checked this.
There is a huge drain from the battery when then engine is not running, battery completely flat after two hours standing. I have taken out every fuse and still the battery drains. There is no problem with the starter motor draining power.
The only conclusion I can come to is that the alternator is somehow making the drain, forgot to mention that with the positive battery terminal disconnected the battery shows 12V with it connected, all fuses out and no engine running it shows just over 3V
A new alternator is very expensive and I don't want to buy one just to check it, any ideas anyone ??
Thanks,
RS

[assassin10000]

rotational spare Wrote:The battery light does not come on at all but the car starts ok, the battery light does work, I have checked this.
There is a huge drain from the battery when then engine is not running, battery completely flat after two hours standing. I have taken out every fuse and still the battery drains. There is no problem with the starter motor draining power.
The only conclusion I can come to is that the alternator is somehow making the drain, forgot to mention that with the positive battery terminal disconnected the battery shows 12V with it connected, all fuses out and no engine running it shows just over 3V
A new alternator is very expensive and I don't want to buy one just to check it, any ideas anyone ??
Thanks,
RS

How old is the battery? Maybe try a different battery, batteries can go bad and "dead short" internally.

What was the voltage with the engine running?

Andrew

[Lipinhu]

With the engine running and idling fine, you should get something arround 13/14V. From what you described, to me its all about the alternator.
1st- dont go and buy a new one, there are parts that are ment to be worn out after all these years, but you can esily repair it. My guess is the brush (or whats left of it) or the rectifier, once the stator doenst have much (if any) wear.

There are a repair kit at toyota (27362-18011, dont know how much costs) that brings the rectifier and the main brush. I think it will get you running like new. Another option its to look some junkyards arround and look for a Denso alternator with the same bolts place, there are lots of compatible and better ones.

I been in trouble with the alternator on other cars and allready checked it on my hachi, so...

[Jousi]

Maybe the diode-pattern is broken from alternator. It causes similar problems. Put a kill-switch on the battery :wink: .

[totta Crolla]

Thanks everyone, definately the alternator..... just deciding what to do next