Welcome to Just Commodores, a site specifically designed for all people who share the same passion as yourself.

New Posts Contact us

Just Commodores Forum Community

It takes just a moment to join our fantastic community

Register

do i need a new alternator

vxs93

Member
Joined
Nov 20, 2012
Messages
133
Reaction score
0
Points
16
Location
melbourne
Members Ride
2002 VX s-pac manual
Hey everyone

I have a vx v6 commodore with approximately 220000km on it.
Yesterday night i was cruising on the freeway at 100kmph when suddenly the head unit shut off, i kept driving for about 1km then all my guages stopped working and some of the fault lights came on along with some beeping. At this point i pulled over straight away.
I got the car towed home with racv and it wont start at all, the battery is drained.
Im guessing the alternator has gone, im just wondering if you guys think this is the case or if it could be something else.

Cheers guys
 

accentstencil

Well-Known Member
Joined
Jun 30, 2005
Messages
8,376
Reaction score
586
Points
113
Age
71
Location
Caboolture South, QLD
Members Ride
WH II Caprice, 5.7 2018 Equinox LTZ V
It sure sounds like the alternator, mostly likely a new voltage regulator will fix it.
 

dirty hands

Active Member
Joined
Nov 25, 2013
Messages
1,445
Reaction score
11
Points
38
Location
ipswich qld
Members Ride
magna
alternator needs to be checked

surprised the battery charge dash light wasn't flickering to give you warning of eminent failure

possible regulator
if not the whole thing

if any more problems like that ... might be the battery as well

dont think being Halloween had anything to do with it :flame:
 

MYVESSV8

Well-Known Member
Joined
Nov 28, 2009
Messages
3,074
Reaction score
330
Points
83
Location
Brisbane/GoldCoast
Members Ride
VE 6LT M6
battery or alt, charge battery if you can, if the reg is stuffed you just by a new one (it includes brush's) two screws and away you go, seeing as its done hi k's maybe the slip rings could do with a clean-up as well
 

vxs93

Member
Joined
Nov 20, 2012
Messages
133
Reaction score
0
Points
16
Location
melbourne
Members Ride
2002 VX s-pac manual
Thanks a lot everyone

Yes dirty hands i forgot to mention i did notice the battery light flicker a few times while i was driving on the freeway.

Sorry but i dont know what a voltage regulator is, i was just going to go to the local wreckers tomorrow and pick up an alternator. And also im hoping its not the battery aswell because the one i have is only about a year old but it has warranty.
 

accentstencil

Well-Known Member
Joined
Jun 30, 2005
Messages
8,376
Reaction score
586
Points
113
Age
71
Location
Caboolture South, QLD
Members Ride
WH II Caprice, 5.7 2018 Equinox LTZ V
Thanks a lot everyone

Yes dirty hands i forgot to mention i did notice the battery light flicker a few times while i was driving on the freeway.

Sorry but i dont know what a voltage regulator is, i was just going to go to the local wreckers tomorrow and pick up an alternator. And also im hoping its not the battery aswell because the one i have is only about a year old but it has warranty.

The voltage regulator is the black box at the back of the alternator. Should be around $50 for a new one as opposed to a used alternator for probably around that price.
 

diysv6

Active Member
Joined
Dec 17, 2005
Messages
547
Reaction score
28
Points
28
Location
SEQ
Members Ride
VF S1 SV6 STORM A6: VZ S1 SV6 A5
I have been working on my son's VT recently and his alternator was playing up (V6). Low charge voltage with AC and headlamps on - about 12.8v from memory. Wrecker unit $100.

Just a thought.
In passing if you have a power steering leak in the reservoir, hoses , pump area, I understand the power steering fluid can be sucked into the alternator and causes sticking of brushes, fouling the slip rings and possible overheating and failure. In the old alternator the windings were black not the varnished copper appearance. His reservoir hose clamps and pump were leaking. Don't know if the original varnished wire was black or what. Cleaning the slip rings there was a slight trace of goo, not carbon dust only.

A blown lamp in the dash will stop the alternator charging on engine start.
Garage talk has it that just about every VT alternator suffered an overheating problem. The VT weakness was the charge cable crimp connector at the rear of the alternator. It failed, over heated, and then in some cases took out the alternator's diode block.

Some notes about brushes and voltages if that helps (from Haynes service manual) -
Brushes Spec max 12mm long, shortest 3.5mm. Spec for rotor is for 2.4 ohms for original Bosch VT alternator.

At 1275RPM and 5/10A load, the alternator should not drop more than 0.5V from the initial 14.2 to 14.6 volts.

Wiring, cable joints etc voltage drop test:
At 2500RPM, headlamps on, there should be no greater than 0.5v and 0.25v on alternator to battery, and battery negative to earth cables respectively. Engine off, the voltages should be no higher. Any change points to charging wiring faulty with engine running or fixed wiring problem with engine off and battery discharging.
 
Last edited:
D

devilly

Guest
easy way is charge up battery,then before you start car.
hold mode and up, start car release buttons ,then press mode to get to on board volts.

you have more then 5 clicks on mode for different things.

then when it's sitting on idles,apply brake and release and see if volts drop and then go back up.

battery should be 12.something and onboard should be 14.something.
 

amg

New Member
Joined
Apr 2, 2014
Messages
54
Reaction score
3
Points
0
Location
Melbourne
Members Ride
Holden
If the alternator has 220K then it could be time for a new one.

I did the replace brushes on the regulator trick when the alternator light started flashing on the dash. Checked voltages and although not perfect they were still in tolerance.

Lasted about 500km when the battery exploded making a hell of a mess.

New battery and swapped the old alternator for a reconditioned one from a reco shop. New alternator read perfect voltage.

If you can't test it fully and properly yourself better to have the peace of mind and get a certified replacement.
 
Top