alternator test
19 February 2010, 12:00 PM
#3
Guest
Posts: n/a
19 February 2010, 12:11 PM
#4
Scooby Regular
Join Date: Nov 2009
Location: plymouth
Posts: 415
Likes: 0
Received 0 Likes
on
0 Posts
borrow a voltmeter and put red/black on battery terminals.
then start car and should be reading 13.5 to 14.5 volts,then turn on heater,rear screen,lights etc and check you still have at least 13 volts.revving car should also raise the voltage slightly.
if not alternetor fooked.
then start car and should be reading 13.5 to 14.5 volts,then turn on heater,rear screen,lights etc and check you still have at least 13 volts.revving car should also raise the voltage slightly.
if not alternetor fooked.
19 February 2010, 12:21 PM
#5
cheers rifleman
i have a boost/ battery voltage gauge in my car.. when the car is running its reading 14.8v turned the heating,rear window heater,radio,lights on and it dropped by 0.2v went to 14.6v
does that mean the alternator is ok?
i have a boost/ battery voltage gauge in my car.. when the car is running its reading 14.8v turned the heating,rear window heater,radio,lights on and it dropped by 0.2v went to 14.6v
does that mean the alternator is ok?
Last edited by powerwrx; 19 February 2010 at 12:26 PM.
19 February 2010, 12:34 PM
#6
Scooby Senior
iTrader: (3)
Join Date: Jun 2006
Location: Slowly rebuilding the kit of bits into a car...
Posts: 14,333
Likes: 0
Received 0 Likes
on
0 Posts
Alternators fail in three ways :-
1. Mechanical - bearings fail
2. Charging - it doesn't.
3. Diode packs break down - current leaks whilst stood, thus flattening the battery.
Yours passes the first two, an auto-electrician can check for 3.
IMHO.
dunx
P.S. Is it caused by "Tracker" related issues ?
1. Mechanical - bearings fail
2. Charging - it doesn't.
3. Diode packs break down - current leaks whilst stood, thus flattening the battery.
Yours passes the first two, an auto-electrician can check for 3.
IMHO.
dunx
P.S. Is it caused by "Tracker" related issues ?
Trending Topics
19 February 2010, 12:43 PM
#8
Scooby Regular
iTrader: (12)
Join Date: Mar 2009
Location: in a house
Posts: 2,078
Likes: 0
Received 0 Likes
on
0 Posts
ammeter is needed.
start the car and put the pins on battery terminals. correct way of course
should see 13.5v+ when car is on.
when the car is off you should see 12.7v+ (anything below 12.6, would indicate battery is on its way out)
start the car and put the pins on battery terminals. correct way of course
should see 13.5v+ when car is on. when the car is off you should see 12.7v+ (anything below 12.6, would indicate battery is on its way out)
19 February 2010, 01:08 PM
#10
Scooby Senior
iTrader: (3)
Join Date: Jun 2006
Location: Slowly rebuilding the kit of bits into a car...
Posts: 14,333
Likes: 0
Received 0 Likes
on
0 Posts
When the "Tracker" unit doesn't power down ( 1 hour usually ) it continues to draw a "on" current.... sadly calling them out for a look will cost you plenty.
If you could find it you could un-plug it and insert an ammeter to monitor it's current draw. Or phone them for a system check and ask if they are aware of any issues, with the system.....
HTH
dunx
If you could find it you could un-plug it and insert an ammeter to monitor it's current draw. Or phone them for a system check and ask if they are aware of any issues, with the system.....
HTH
dunx
19 February 2010, 01:22 PM
#11
Scooby Regular
Join Date: Nov 2009
Location: plymouth
Posts: 415
Likes: 0
Received 0 Likes
on
0 Posts
the cold weather we have had lately is buggering up loads of batteries.the cold can make them drop a cell.did mine last week after same thing,
£78 from halfords for a super dooper one(good old forces discount)
£78 from halfords for a super dooper one(good old forces discount)
19 February 2010, 04:23 PM
#13
very true, just been to kwik fit for them to check the battery state, on his meter it came up with
*battery undetectable.. at 55%.*
what ever that means.
and to top it all off, the young lad told me to drive in but there was a slope into the bay , he stood and watched me slowly drive forward and instead of telling me i couldnt make it i caught my splitter on the floor which resulted in a big chip coming off it and all scraped underneath.then he just walked off.. the PR*CK!
*battery undetectable.. at 55%.*
what ever that means.
and to top it all off, the young lad told me to drive in but there was a slope into the bay , he stood and watched me slowly drive forward and instead of telling me i couldnt make it i caught my splitter on the floor which resulted in a big chip coming off it and all scraped underneath.then he just walked off.. the PR*CK!
Last edited by powerwrx; 19 February 2010 at 04:50 PM.
19 February 2010, 08:00 PM
#16
Scooby Regular
iTrader: (6)
Join Date: Jan 2009
Location: on sunny ibiza ocean beach
Posts: 5,594
Likes: 0
Received 0 Likes
on
0 Posts
i know that craig razor wrx has suffered the same problem he has had his front belt replaced this week and so have i due to the cold weather fooking them up power steering juddering but this belt runs through the alternator be interseting to see if his is still losing power now
19 February 2010, 08:57 PM
#17
Scooby Regular
iTrader: (21)
Join Date: Mar 2009
Location: Manchester
Posts: 3,757
Likes: 0
Received 0 Likes
on
0 Posts
I'm not a expert but i've had 3 batteries in total. 2 in the past few months! Only use mines at weekends. Kept going flat, bought a new one and the same thing happened within 4 weeks. Checked it on my meter and it wasn't the alternator. Took it back, the guy changed it after afew words. Then he tested it with the car running and all electrics aircon lights on etc and said I had a faulty alternator. Got my multi reader on it again and it was fine. Robbin b######. Took it to ricks in Stockport to be sure, he checked everything and its fine. Must have been a dud battery. Had the power steering/alternator belt and aircon belt changed last weekend. Was sqeeking like mad when cold. All seems ok so far, used the car before for the 1st time since last Saturday. All ok! The cold weather doesn't help tho. Hope this helps you out in someway!
19 February 2010, 09:29 PM
#18
not got to the botom of my issue yet, going to test it with a multimeter on monday and see if theres any voltage drain anywhere. alternator seems to be working as it should but i need to test the diode packs on it. also been told that it could be caused by a faulty starter motor so gonna look into that too.. process of elimination i think
19 February 2010, 09:36 PM
#19
Hi again!
If you need help, explinations of possible causes, let me know, can help you over the phone.
By the way, I am an ex auto sparky so did this stuff for years lol
If you need help, explinations of possible causes, let me know, can help you over the phone.
By the way, I am an ex auto sparky so did this stuff for years lol
19 February 2010, 09:42 PM
#20
Scooby Regular
Join Date: Oct 2007
Posts: 1,328
Likes: 0
Received 0 Likes
on
0 Posts
bear in mind the limitations of the so called 'smart' alternator. it will only charge the battery if there is a constant current draw. i.e. sidelights on or blower on. if a battery is allowed to go flat regularly, it can permanently damage the battery. i am not sure if all the newage models have a smart alternator though..
19 February 2010, 09:53 PM
#22
bear in mind the limitations of the so called 'smart' alternator. it will only charge the battery if there is a constant current draw. i.e. sidelights on or blower on. if a battery is allowed to go flat regularly, it can permanently damage the battery. i am not sure if all the newage models have a smart alternator though..
sounds good to me mate, if i need you ill give you a ring for some advice. it would be good to have some ideas of what to look for too
19 February 2010, 09:58 PM
#23
No problem. By the way, there is no such thing as a smart alternator! there are two types, one that uses the battery voltage at its + terminal to charge and dictates power ampage via this reading. Other is dont via an ignition feed to the regulator. First check, does your battery warnning light come on with ignition? Yes, regulator ok so far. Does it go out when the engine runs? yes? Regulator is ok. Does the warning light glow? Does it glow brighter if you put heated rear screen on etc? Yes, Rectifier (Diodes) is knackered. If the light is on before starting and off when running, 98 % alty is good!
19 February 2010, 10:08 PM
#24
battery light comes on and goes off as it should, no slight glow on dash board.. cars running voltage is 14.8v..swich on lights , radio, heated rear screen etc and the voltage drops by 0.2v something and nothing.
once the car is running all is ok.. its just the starting period. kwik fit told methe battery was only at 55%
once the car is running all is ok.. its just the starting period. kwik fit told methe battery was only at 55%
Last edited by powerwrx; 19 February 2010 at 10:10 PM.
19 February 2010, 10:11 PM
#25
That alty is fine. Normally its 12V standding there abouts. 14.2v running at 1200 rpm, main beam, heater, rear window, should be around the same. if it is, all with alty is ok.
19 February 2010, 10:22 PM
#27
I would say yes. You need the amp meter to check for a drain first. A golden rule for everyone is that, an alternator is only designed to put back what a start takes out and to keep up with car power requirements. Bump starting a flat battery car and reving it, then a drive with lights on etc will not solve the problem, next morning, will be flat again. if in doubt, charge with a trickle charger over night!
19 February 2010, 10:26 PM
#28
yes thats my plan for tomorrow night, trickle charge over night then get a meter on it on monday... am i right in saying i have to dissconnect the live from the battery then make a connection again using the prongs on the multimeter one on the live lead and the other on the live terminal.
ive been told that anything over 0.9v on the reading means i have a draw somewhere
ive been told that anything over 0.9v on the reading means i have a draw somewhere
19 February 2010, 10:30 PM
#29
Use the neg, not pos. Always disconect the neg first, Safety! If the spanner touches the body work, no harm done, do it on the pos first, problem! I normaly say anything above 0.15A to 0.20A is boarder line. I guess you will see, if drain is a fault, Tracker etc, 0.75A to 1.0A