hi all,

today my charge light came on whilst driving, so checked connections etc and decide it must be a faulty alternator, got and fitted new alternator, still the same.

x flow engine, lucas lra100 alternator(2 big connections, one small),vicki green wiring loom.

any help/ideas appreciated!!

Ray

Did the voltage regulator get changed also?

according to the book, its part of the alternator, so yes it did.

Ray

Put your voltmeter between the main charge output (that goes to the battery), and either your engine block or your earthed alternator casing.

You should see 12-13v.

If you do then you know the alternator is working so it must be an earthing/wiring problem.

If your not seeing 12-13v then it's a problem with the alternator still!

Could it be an issue with the +12v supply to the alternator? Check the charge light bulb is working as it's this that supplies the alternator. The may also be a +12v feed direct from the ignition- check this is working too.

Not sure what else to suggest- only just got mine going!

Hope that helps,
James


[Edited on 9/8/05 by James]

Pull of the field wire (small one from the warning light to the alternator) and isolate/insulate it. Then turn on the ignition and see if the warning light comes on. If it does you've got a wire touching earth somewhere.

hace already checked on the output from the alternator wasn't getting any voltage, will try insulating the small wire.

does the alternator have to turn in a certain direction?? woudl it not work if it was going the wrong way??

Cheers

Ray

Where did you check for alternator output.
DO NOT run it without the battery connected. Check for voltage at the battery it should rise from 12v at engine off to 14v with engine running. If not move the live probe to the heavy terminal at the alternator and see if there is 14v here if tes check your main wire to the battery it must be broken. Also check the engine earth strap is ok. And lastly yes some are rotaion direction sensitive.


OOps just read James post. I must learn to type with more than 1 finger

[Edited on 9/8/05 by omega 24 v6]

checked the output from the alternator on the thick brown cable(which goes to the battery), the voltage at the battery is 12.6 volts @2000rpm

have put a jump lead from alternator casing to battery -ve, still the same

Ray

Yes but also check it at the back of the alternator with it running.
CAREFULLY

[Edited on 9/8/05 by omega 24 v6]

Probably worth checking the large bnlock connector at the back of the alternator , sometimes the connections get damaged.

Most common problems with new Lucas ACR alternators is bad connections on the large blade termminals --- usual scenario is new alternator is fitted and it stops charging after a short time. In the slightly longer term any arcing at the spade terminnals will ruin the alternator and damage any electronics in the car.

Correct way to test a Lucas and most other alternators is.

(1) Check battery voltage -- should be at least 11.8 volts or the battery should be charged before testing the alternator.

(2) Connect voltmeter across battery and rev to 2000 to 3000 rpm --- voltmeter should read more the 13.4 volts but less than 14.8 volts.
(3) Repeat the test with headlights on (and HRW in a saloon) again voltmeter should read more the 13.4 volts but less than 14.8 volts.
(4) Now turn head lights off again voltmeter should read more the 13.4 volts but less than 14.8 volts. with no major spike in voltage.
-----------------------------------------------------------
Any less than 13.4 volts and battery won't get charged more than 14.9 and thelight bulbs will blow.

There are other checks to look for leaking dodes but the above is the stasndard test.

[Edited on 9/8/05 by britishtrident]

Right!!!!,

have found that with the battery sat at 12.6 volts, i am only getting 10.5v at the alternator(through the battery warning light).

i ran a wire straight from battery +ve to the alternator(to where the cable from the warning lamp would have been connected) and obviously the lamp wasn't on at all, but the voltage at the battery jumped straight up to 14.2v with the engine running.

the system has been working in the past, the only thing i can guess is with the battery voltage higher it was pushing just enought throught the lamp to "power" the alternator.

so the choices are find a different lamp with a lower voltage drop across it, or link it out and fit a volt meter to monitor the battery charge state.


thanks for all your help/suggestions.

Ray

Ok i seem to recall in the depths of past knowledge that on acr's the warning light bulb needs to be a minimum of 3 watts I hope someone will back this up for me.
So maybe all you need is a new warning light bulb perhaps.