what would cause an alternator to keep die-ing?

**Garth AE86** · 29-03-2006, 09:01 PM

mine keeps blowing itself up
"reco'd" it for $220 bucks 25 days ago
and now dead

its not the reg
and the brushes were great

it ran solid 14.0 at idle until it just died completely tonight
fucks me how it happens

checked wiriing and fuses.. all fine

can any electrical engineers/mechanics explain??

**EldarO** · 29-03-2006, 09:15 PM

internal short, water getting inside it, someone stabbing it with a screw driver, cable loose/broken/frayed/not doing what its supposed to be doing.

more info, what were you doing when it stopped working? are you sure the cable isnt just loose? are you sure the cable that "tells it to charge" is making a connection?

i dont know whether yours is a genuine jap ae86, but we had an issue in my mates ke70 (same shit) where we didnt connect the wire to the alternator properly, not the big thick on, the one that tells it to switch on, so nothing worked.

if yours is a home-made (not saying its not quality!) job, it'd be worth a look...?

Eldar.O.

**30psi 4agte** · 29-03-2006, 09:19 PM

Where are you testing for voltage or back of alt?

**turbo ke20** · 29-03-2006, 09:52 PM

what you should have is a battery supply which is the stud with the thicker wire going to it.
then depending on what alternator you have there will be two other wires. if so they are usually labelled L and S
L stands for warning light. if this is not connected the alternator will not charge. to check this wire, earth that wire out or probe it with the test light lead on negative and there should b a dull light and your warning light will glow. or easier just earth that wire and the light will glow. if the warning light comes on in the dash thats OK
secondly the S is for ignition sense wire. this should be 12v when ignition is turned on.
if all three of your supplies and outputs are OK the fault is in the alternator. hope this helps you out.

justin

**Garth AE86** · 29-03-2006, 10:36 PM

im checking it all with an multimeter
from alt and from battery on and off
plus my SAFC tells me voltage

well i DO have a drop vent hood
water COULD get into it
but its been like that for 2 years
it only started happenning recently

ps its a genuine JDM ae86 but everything is connected as it should be ie OEM factory
the plug is done correctly i assume and all is plugged in and attched correctly
i was driving when it stopped working

**oldcorollas** · 29-03-2006, 10:42 PM

been doing high rpm recently? reco schmeeko, if they haven't paid attention to the solder joints between the coils and the field diodes etc, high rpm vibration will kill them...

what died in the alt? that is a more important question, which will tell you why it's happening..

how is your battery? is the alt having to kick out a heap of current to try and get it charged?

14V at idle??? at idle (unless yours is high) it should be just dropping off voltage...

checked the tightness of bolts between the alt mount and the block? no paint anywhere stopping connection, ie on the fresh alt?

**Garth AE86** · 29-03-2006, 11:15 PM

thats what im thinking - fucking bullshit auto electrician never did shit
4 hours to 'completely recondition it bro' yeah fuckign right.... 10 minutes to paint it sillver and replace the brushes you con artist...
they never said what was wrong, just that they replaced the entire internals and it cost $220.. yeaaaah thanks 'sik bro'

i do high rpm 7000+ all the time. should be ok though? or not?

i havent checked the block and the alt mount - excessive vibration you think?
the paint is not an issue - its been working since i got it 25 days ago.. then fucked.. just like that

the idle is high - 1300rpm but it still gets 14.0 ~ 13.8 consistent idle

the battery is OK i think, would it really cause an alt to die though?
connections and plugs all secure - no issues there

**oldcorollas** · 30-03-2006, 01:09 AM

when they said replaced all internals... that meant bearings, armature etc?? likely not...
surely it has warranty of at least a month??? quick!! take back

rpm can kill due to harsh vibration breaking internal reg or wires or solder joints. probably ok tho...
ahh with idle that high it should be charging then.

i'd be taking it back and ask them to SHOW you what went wrong

it should have a warranty, and so should be replaced....
ask to be present when they dismantle it, so you can have a good look at the insides.. see if they are new or not

take pics and post up too

i wanna see sik bros bodgy job (or perhaps not bodgy

)

**Hydra** · 30-03-2006, 07:18 AM

$220

I just had mine done for $132

I'm going to pick it up today, but the guy said it was simply "worn out" when I spoke to him on the phone. I can understand this - the alt is a good 20+ years old now.

**The Witzl** · 30-03-2006, 08:14 AM

MacGyver Sez!

**Hydra** · 30-03-2006, 11:38 AM

lol...

I got my alt back today, they gave me a whole $2 discount for paying cash

They didn't give me an actual breakdown of what was wrong, they just said almost everything was worn out. Who am I to question this? Installed it once I got home - works perfectly. Suppose they were right then. 12 Month warrenty too - should be fun if it happens again.

So I can now safely say that $220 seems a bit steep.