Alternator short dead?

[AB]

Had a scary ride home with no alternator and battery down to 6 volts from SA yesterday.

Did some tests today and only 0.15V coming from the rear cord. I thought mud might have ruined the alternator but after looking around I saw a spark and noticed the rear cable feeding the crank battery had worn and rubbed onto the metal A/C hose.

Using a multimeter whilst car on confirms only 0.15V coming out. I'll take the alternator out this weekend but what do I look for?

Is the alternator completely ruined, is their a fuse or something inside the alternator at all to replace?

Any help appreciated!!!!

[Yendor]

If you only have .15v on the large White wire at the back of the alternator you have blown a fusible link.

You should have at least have battery voltage on the large White wire.

Check your fusible link, if this is blown replace it then recheck alternator output.

[AB]

Thanks Rod, where is this fusible link?

The reading above was directly off the back of the alternator, the bolt thread thing that comes out the back where the white wire gets connect to which goes to the battery.

[Yendor]

It is in the fuse box near the main battery.

It will be a large fuse, around 60-80amps.

That large White wire on the back of the alternator as you said "goes to the battery" this should have the same voltage reading as across your battery (around 12 volts).

[AB]

Yeah all those are fine, black IGN fuse, the glow and the three green and brown ones are all ok.

The volt reading when the battery is charged at the white wire near the back of the alternator is ok at 12 volts.

When engine started it drops to 11.7 volts and doesn't rise.

When engine running I disconnect the white wire off the alternator and the reading just off the bolt at the end of the alternator (white wire not connected) is 0.15V.

I'm thinking the actual alternator is dead as it is not producing zip??

Maybe either the short did something or mud got inside and ruined it but it looks super clean from where I can see.

[Yendor]

Ok,

You should never disconnect the battery or alternator while the vehicle is running.

What can happen if you do this is, the system voltage can rises so high that it blows all other electrical items.

As long as your alternator/battery warning light in the dash still works then yes your alternator is stuffed, more then likely blown the power diodes in the rectifier.

[AB]

Thanks Rod, I'll know next time....Jeesh Ive done that about a dozen times today too!!!!

Ok, so I have an auto elec mate down the road. Is it worth taken it off and give to him or buy another one.

I can get the same one again with trade discount for $300....

Thanks for your help mate!!!

[Yendor]

It's only a problem if the alternator is working.

I have been out of the game for about 10 years so I can't really comment on prices.

I would have a talk with your auto elec mate, he would be the best one to advise on that.

Depending on parts availability it might be better to get a new one.

[dan&tamspatrol]

take it to the mate that way you will know for sure

[AB]

Thanks Lads, I'll let you know the outcome....Can't wait to take it out either....Pain in the....