alternator (i think) problem

[defecat0r]

Hey guys, so i noticed my battery indicator came on on the dash today, so i've just been having a dig around trying to find out what's going on.

With the car running i'm measuring 11.8V at the battery, so the alternator is obviously not charging at all.
Measuring from the big positive terminal on the back of the alternator to the +'ve on the battery is a straight short, as is from the -ve on the battery to the housing on the alternator.

I had an old alternator lying around that i replaced earlier this year as it had some very noisy bearings. I pulled the regulator off and swapped it with the one from the old alternator to start with, without disconnecting the alternator, and it sparked a bit when i took it out, so not sure if thats killed something :S But since then i've tried both alternators with each regulator and nothing

Now what i'm wondering, is how do you test a regulator with a multimeter? what are you looking for to know it's working? is there any way or do you simply need to replace it with one you know is working?

here's a pic to make it a bit easier. I've also measured about 6 volts from the plug that connects to the A and B on the pic with the car's ignition on. That sound about right?
Thanks guys!

 

[Vt-Brrrlina]

i go the gregories manual and it says to just change it - says nothin bout being able to test that part - however there is parts inside the alternator that can be tested if ya pull it apart.. other than that jst the tests youve done testing how much ya battery is chargind at should be around 14 volts

 

[Chirpstr]

Check what it's putting out while she's running. Should be around 14.4v coming from the reg plug. I'll be getting a new reg for the alternator if it's not near that spec. If it's ok then it would have to be the battery at fault.

 

[defecat0r]

ahh alright, guess i'll just take it to an auto electrician tomorrow then and see what he says. Don't really wanna risk driving to wreckers and having it run outa juice if it's not that, even if it is more than likely.

And yea, tested at the red plug and it's 11.8, so doing nothing, very broken

 

[defecat0r]

so i've just got back from the auto electrician now. Tried another alternator and no go, turned out that the "fusable link wire" coming off the battery was corroded, basically ripped appart in his hand, so replaced that and she's all good. Apparently if that's not connected the regulator won't turn, but i don't understand why i was getting continuity from the alternator to the +ve on the battery.
who knows, she's fixed so i'm happy, moral of the story, keep your battery terminals and everything hanging off them clean

 

[sacha]

hi i dont know if you can help me or anyone else can but im having problems getting the alternator off. its disconnected from everywhere but there is no gap for it to come off.
seeing that you got your alternator off sometime this year i was wondering if you could help me with mine. do i have to disconnect something else to get the alternator off. i searched the whole internet can't find what i need to know. everyone makes it sound easy that you have to disconnect the wire and it just comes off, but it doesnt all the wires are off but there is no space for it to come out. do i need to disconnect something else.
my car is a vk commodore berlina . i would appriciate it if i get a reply.
thanks

 

[Warranty Void]

Start your own thread mate you'll get heaps of replies.