Scoty

Hello,

Can anyone help me with this please.

My car failed to start last week. (battery was flat first thing in the morning)

I got a jump start, and checked the Link module to see what voltage the alternator was putting to the battery.
It read 14.3 volts.

So I asumed my battery was nackered and the alternator was working, and got a new battery fitted. (same day)

Today the same thing has happened. The car fails to start because of a flat battery. Again, I got a jump start.
This time the Link reads 12.2v. I checked the earth strap, and the started motor for loose connections, but it looks OK. There is no corrosion on any of the terminals, and they are tight.

Can this still be the alternator that is faulty, even though the Link is showing that is is working OK?
Is there anything else I can check, maybey something simple....fuses

Thanks

Scoty

Scoty

Forgot, that the battery light in the dash stays on all the time when the car is running.

Andy.F

Sounds like one of the diodes in your Alternator have failed. It will still charge with reduced current flow but will leak away battery current when standing idle.
Most auto electricians can replace the diodes / rectifier pack. Not too expensive, £20 ish IIRC.

Andy

LG John

Sounds like the car isn't being run enough. I would suggest you take it for a drive.......but.....

Are you sure you aren't leaving all that ice running

Andy.F

I'll hold him while you hit im Scoty

Scoty

With pleasure Andy

LG John

He, He Hope you get it sorted. If its any consolation my battery is showing signs of weakness on startup

SCOSaltire

lol
so is mine.. lights dim when locking the doors

LG John

I had to switch my 'bright' switch to dim mode to conserve power

tweenierob

Have you checked the drive belt??
A friend with a Golf had exactly the same prob, belt didnt screech at all..
Wouldnt start in the morning(flat batt)/light on whilst running/lights would dim whilst driving etc etc
Checked the voltage at idle and it was about 12.6v (not good) when i revved the engine the voltage dropped to 11.9v.....

Changed the drive belt and 'hey presto' 13.7v

I did try tightening the belt but it made no difference.

Just a thought??

Rob

Scoty

Cheers Rob,

I checked the belt. It's in good nick and tight enough.

What Andy has said is going to be the fault probably.

Thanks for everyone's help.

mmurray75

The way to tell if the diode has gone bad is to check the output of the altenator with a volt meter set to AC voltage. On a good alt you should see around 0.03v AC on a bad one the AC voltage will be much higher. hope that is of some help.

darms

iTrader: (5)

Why not try

http://www.scoobynet.co.uk/bbs/threa...hreadID=181616

SCOSaltire

that was cleverly funny kenny

[Edited by SCOSaltire - 3/4/2003 9:49:49 PM]