Electrical problems(batt light) help please, alt?

[brent88]

Hey, was driving my FTO today and the batt light is stuck on, volt gauge reads 9v-startup idle, 10v warm idle, 11.5 from 3.5-8rpm(batt light dims then disappears in this rev range) sounds like the regulator on the alternator maybe.

Replaced the alternator 6 months ago with a 2nd hand 1(not reco'd)$220 as new 1's were between $450-$930 and auto elec couldn't assure me it would work if he replaced the part as its a mivec (4 pin, controlled by ECU) my last alternator went crazy and was charging from 14-18 volts.

Terminals are clean and done up tight and batt is under a year old and is a large size. Alt belt is fine and the right tension. i did disconnect the battery 4 days ago to clean the stepper motor and had the batt disconnected for 1.5hours.

Any other tests i can preform or any conclusions that anyone has drawn that they want to share?
Appreciated.

[bduffman]

That's f**k all volts mines never that low
Mine always sits at like 13 volts or so off and running
If you have a volt metre you can test the battery volts ( engine off ) and check alt while on

What are you running extra that could be drawing the current

[vipfto]

alt is shot

[brent88]

yeah figured it was shot, gonna put batt on charge for an hour this morning and see how long it takes of driving till the batt light comes on again. at low revs there is a slight whirring too i think....maybe a bearing in the alt?
gonna ring some wreckers and try n buy a new 1 and just drive the car small distances if i absolutly have to and keep the revs up

[brent88]

ok, idle is at 1,500rpm now so batt light is only dim on idle that should buy me a little time ill just put car in neutral at lights to save the stall converter, i know it might not seem like a good idea to raise the rpm as a temporary measure but its better then fcking my elec's and if i can find an alternator i wont be able to put it on till sunday and will have to use car to get to work(12 mins) some of those days.

still going to charge batt just incase its faulty.....doubt it

[bduffman]

well work car had a battery under a year old die on us had to get a new one

why not call around and find out how much it is to rebuild your alt

[brent88]

nah batt is fine, lookedd at rebuilding alt last time but the auto elec couldent guarentee that it would work because his machine couldent properly test the alternator due to it haveing 4 pins(mivec) so the computer can controll the current etc via the ecu. maybe its a different situation with this problem of undercharging as opposed to the overcharging last time but im getting a 2nd hand alt 4 $180 which is pretty cheap from a wreckers.

from memory its $200+ to rebuild an alternator

[dstocks]

There was a guy out of melbourne selling new ones for a good price. Cant remember the details, but pointed a few people to him a month or so back. You might find the thread if you search.

[brent88]

yeah thanx dstocks did some searching but confirmed what i already thought, gpx alternators arnt able to be reconditioned with a 100% guarentee due to the 4 pins (2 that go to the ecu) hence the ecu could be the problem. new ones are $450+ (last time i rang all the major chains and looked around the internet) hopefully ill get lucky and this wreck will have had a new 1 not long ago. getting it in a few hours, i can live with $180 when the prices range from $450- over $900 new

[bduffman]

should have bought new the first time and you would be at even with a better alt lol

[brent88]

yea dunno, maybe....... i guess i was unlucky, the alt i put in didnt look that old really, hopefully within 3 years i will sell the fto and buy a wrx, supra or s15, i installed the last 1 myself and i will install this 1 myself too so there is no more outlay just 2 hours

[payaya]

Whirring is a sign of a bad alternator. Auto elecs can rebuild it if you can't find one.