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[ali]

I would like to check alternator wires to see if they are my non charging problem what ones could it be and what should the meter reading say :-/ The battery stopped charging ( its a new battery ) so I changed alternator a few weeks ago, worked ok for a couple of weeks but its now gone back to the same problem of not charging. A garage confirmed it was the alternator first time round but I never checked any wires, not sure they did either.

[rustym95]

I would just check the wires with the battery off, test with a multi meter, as most fault of not charging is the relay, iver in the alternator or on the retern systerm that checks there is a battery connected.

[TheBoy]

2 wires, bigger one goes on bigger stud, samller one on smaller stud

[KillerWatt]

I would just check the wires with the battery off, test with a multi meter, as most fault of not charging is the relay, iver in the alternator or on the retern systerm that checks there is a battery connected.

Cut-off relays are 30 years ago, no such thing these days and hasn't been for god knows how long.

@ the OP

Disconnect battery
Disconnect alternator wiring
Check for continuity between thick lead at alternator end, and positive battery lead
Check continuity between alternator body and battery negative lead
If both above are good, reconnect battery, switch ignition to position II (after ensuring those loose alternator wires aren't touching anything or each other), and you should see battery voltage at the end of the thin wire when measured with respect to ground.

If all above tests are positive, you either have a slack drive belt or the alternator is f**ked internally somewhere along the line.

[Kevin Wood]

Also.. the crimp where the alternator / starter wire terminates at the positive battery terminal has a habit of working loose. Check to see if the terminal gets warm when running or if the wire is loose when twisted.

This can drop enough voltage to prevent proper charging of the battery without there being enough resistance to be notiveable on some meters.

Might be worth working through this if you have a multimeter: http://www.omegaowners.com/forum/YaBB.pl?num=1225724099
 
Kevin

[KillerWatt]

Also.. the crimp where the alternator / starter wire terminates at the positive battery terminal has a habit of working loose. Check to see if the terminal gets warm when running or if the wire is loose when twisted.

This can drop enough voltage to prevent proper charging of the battery without there being enough resistance to be notiveable on some meters.

Might be worth working through this if you have a multimeter: http://www.omegaowners.com/forum/YaBB.pl?num=1225724099
 
Kevin

Good point, well presented 

(I completely forgot that the run from the alternator to the battery wasn't one continuous length).

[ali]

Thanks for that I will have a go tomorrow

[rustym95]

I would just check the wires with the battery off, test with a multi meter, as most fault of not charging is the relay, iver in the alternator or on the retern systerm that checks there is a battery connected.

Cut-off relays are 30 years ago, no such thing these days and hasn't been for god knows how long.

@ the OP

Disconnect battery
Disconnect alternator wiring
Check for continuity between thick lead at alternator end, and positive battery lead
Check continuity between alternator body and battery negative lead
If both above are good, reconnect battery, switch ignition to position II (after ensuring those loose alternator wires aren't touching anything or each other), and you should see battery voltage at the end of the thin wire when measured with respect to ground.

If all above tests are positive, you either have a slack drive belt or the alternator is f**ked internally somewhere along the line.

was thinking of somthing els at time,
would check battery, put meter on batttery and see if any volts are added when engine is running should be 12-13volts make sure that there is nothing on i.e radio e.t.c,, then check it the same way with every thing on there should be no change in volts at battery, if there is then it could be the batery or the volt regulator being faulty.

[Kevin Wood]

was thinking of somthing els at time,
would check battery, put meter on batttery and see if any volts are added when engine is running should be 12-13volts make sure that there is nothing on i.e radio e.t.c,, then check it the same way with every thing on there should be no change in volts at battery, if there is then it could be the batery or the volt regulator being faulty.

With the engine running you need to see 13.5 - 14.5 volts as per the maintenance guide. Any less and the battery will not charge at all.

Kevin

[ali]

after a few checks, the battery wasnt charging but when I connected the other car via jump leads got 13.9 so took off all connections, cleaned them took half my skin off with a wire brush ( only one I had was huge ) checked everything with bleep on meter and also found a loose connection    put it all back together and its charging so thanks everyone 

[Boatboy]

If you've still got the old alternator there is a place in Borehamwood that tests/repairs them. Might prove whether its worth keeping as a spare.

Sounds like you've been lucky this time. Best way to blow an alternator is to disconnect the load whilst its running. (thats how i got to know of the place in Borehamwood)

steve

[shay oneill]

after a few checks, the battery wasnt charging but when I connected the other car via jump leads got 13.9  so took off all connections, cleaned them took half my skin off with a wire brush  ( only one I had was huge   ) checked everything with bleep on meter and also found a loose connection    put it all back together and its charging    so thanks everyone


whitch wires did you clean and whitch 1 was loose i have the same problem on my 3.2

[rustym95]

was thinking of somthing els at time,
would check battery, put meter on batttery and see if any volts are added when engine is running should be 12-13volts make sure that there is nothing on i.e radio e.t.c,, then check it the same way with every thing on there should be no change in volts at battery, if there is then it could be the batery or the volt regulator being faulty.

With the engine running you need to see 13.5 - 14.5 volts as per the maintenance guide. Any less and the battery will not charge at all.

Kevin

constant charge of 14.5volts will blow the battery, or lights or radio. Battery spec's no more than 13.5 volts, says it on all my batterys bar for my lorry battery as that is 24v charge at 25.5volts.

[Kevin Wood]

I disagree. Flooded lead acid batteries need 2.3v per cell for a constant trickle charge and 2.4v per cell for cyclic use.

6 cells in a car battery so 13.8 - 14.4
12 cells in a 24v battery  27.6 - 28.8

http://en.wikipedia.org/wiki/Lead-acid_battery#Voltages_for_common_usages

Even higher voltages can be used for rapid charge applications but battery temperature must be monitored.

Above 2.4v you will get some gassing but it would need serious abuse to "blow" a battery or damage any in-car electronics.

Kevin

[rustym95]

its what it says on the batterys, not what i say it says on the batterys.
and yes that is very nice, but this battery is used in an engine and you go by the spec's of the battery as it say in the linky, and that would be fine on the old batterys but now adays they are seal'd so you dont wont them to get to hot wile they are charging as they go bang.