My alternator light stays on until i rev the engine up to about 2000 rpm then it goes out, also starts glowing at night when on main beam. I have just fitted a brand new one and its still the same so i know my alternator is good.

Any ideas ?

Thanks Simon.

 

Mine has always been the same on various alternators. Never had a problem with it.

 

Maybe a poor earth connection or the actual conection to alternator is loose/corroded. Check output with a multimeter and also across the battery at idle to make sure its ok .

 

normaly its a sign the alternator is soon to R.I.P i would change it or it will only let you down when you most need it

 

love ur avitar..its in he most unbelivable taste.(KENNEY E).RIP
FOOK that makes me feel old..yeah bad earth or do a test on car running
think you want 14.5 volts output on the hot wire side with mult
meter

 

Check the blue wire on the alternator is clean and secure.
Also check that the connector at the back of the dash unit (speedo, etc...) is properly secured and clean. I had that problem and it turned out to be the dash connector coming loose.

 

Frog, thanks mate, i'll check the connection on the back of the instrument cluster.

Simon.

 

if this is a S1 ? then this is normal i have had several all the same the reason it glows at night is that the main beam blue dash lamp and lights in dash clocks leak into battery light area and create a small back light which you can see only at night after checking you have strong charge then this will become part of the normal S1 night time drive i ignore it

 

Its on 3dr cossie, have checked output at battery & its only 13.8 volts but thats with 2 different alternators. Iv'e never had problems with the battery going flat in 2 years, it was just that the light glowed at night on main beam & battery light didn't go out until you reved the engine to 2000rpm , so i thought i better change my alternator before it let me down as i thought it was on the way out. I fitted a brand new one & it was exactly the same, so i suppose it must be a fault on the back of the instrument cluster or wiring but their isn't much wiring really, live cable that goes from the Alternator straight to the battery & the blue wire that goes through to the ignition/dash.

Simon.

 

Did you also change the drive belt to the alternator?

 

Yes it has 2 new drive belts as the old ones were noisey.

Simon.

 

my light comes on at night only, once the lights are on ect it comes on, i have been told to put Ford fan belts on it as they are wider the cheaper aftermarket once and if not Auto sparks in Peterborough will recon the once on the car for £55-£65 fitted.

 

this was what mine suffered with cleaned connections and all sorted

 

You gotta be careful with voltage drops and if it happens when your on boost you'll possibly blow your engine from it leaning the mixture.

HTH

Cheers

Daniel