Lights dim unless I rev the engine then they get brighter??

[BristolSam16v]

Guessing this means my alternator is buggered? Can they be refurbed, and how much would it cost? Also anyone know what rating the alternator is and which ones will fit my valver, ie williams/RT/19 etc? cheers :)

[Laine_16v]

Will only be buggered if the battery light comes on when the car is idling.

[cliolord]

Will only be buggered if the battery light comes on when the car is idling.

unless the battery light is faulty :lol:

[BristolSam16v]

About a month ago it was flickering then staying on constantly sometimes, did this for a couple weeks but hasn't done it since? The battery is now going flat every few weeks (tried different batteries), when it was idling I tried getting the window back up (electric windows) and it wudn't budge!! the lights were really dim until I revved the engine then they brightened up...

If that isn't the alternator what else could it be :S

[BristolSam16v]

Will only be buggered if the battery light comes on when the car is idling.

unless the battery light is faulty :lol:
wudn't be suprised with my car :(

[Purple]

Seems like there's a current drain even when your car's switched off.

Did you install/change any electrical items lately? I would start checking around there.

Or could be bad insulation to earth, check for any bits of dodgy looking cables/connector and clean them up.

Or it might be some electrical component starting to fail. Disconnect some of the equipment and check with the window wind-up test. If it winds up faster, then one of the equipment that was disconnected might be shorting to earth.

[BristolSam16v]

The earth from the battery is perfect, just changed that, what other earths should I check? Haven't changed anything electric recently, why would the light flicker then go off though :(

Also if I start the engine then take the battery leads off, the engine dies straight away... should it do this?

[Dan_mk1]

About a month ago it was flickering then staying on constantly sometimes, did this for a couple weeks but hasn't done it since? The battery is now going flat every few weeks (tried different batteries), when it was idling I tried getting the window back up (electric windows) and it wudn't budge!! the lights were really dim until I revved the engine then they brightened up...

If that isn't the alternator what else could it be :S

Yup, deffo sounds like alternator! IIRC GSF do em for quite cheap!

[BristolSam16v]

Can they be refurbed by an electrician or does it need to be done by a specialist garage?

[Purple]

The earth from the battery is perfect, just changed that, what other earths should I check? Haven't changed anything electric recently, why would the light flicker then go off though :(
Check the earth on the gearbox is clean and tight.

But if you keep having quite severe battery drain, then it's either an electrical equipment leaking (shorted) to earth or the alternator is failing.

If you have a multimeter that can read quite high amperes, you can try measuring the in-series drain current WHEN THE CAR IS SWITCHED OFF. Don't turn on the car when measuring else you will blow the meter. I think anything below 0.1 Amps should be OK. If that reads OK, then good chance alternator is failing.

[Andyvalver]

Alternator :)

[BristolSam16v]

Stupid bloody renault! anyone know if they can be refurbed then?

[cliopete]

Definitely alternator. In fact if you disconnect the battery with the engine running as you said, that in itself will bugger the alternator, so if it wasn't knackered before you did this then it is now. Can also cause damage to other electronic equipment i.e. ECU due to the power surge that occurs as the battery is disconnected while the engine is still running. You can refurb your alternator but exchange alternator from any decent motor factors is your best bet.

[BristolSam16v]

Lol bugger!! They had disconnected before anyway as the terminal on the old battery was ****ed and the negative slipped off so... surely the engine should keep running though even with the battery off?