vectra battery light

[iamelectric]

vectra 2.0l diesel 03 plate

my brothers vectra the dials kept dropping and battery light flashing on , few weeks later it happened again and stayed on so he called out the RAC And the boy told him it was the alternator so he got one from the scrappys and got it fitted , a week later the same thing is happening light flashing on , i have just put my meter on the battery and with the engine off it shows 13v and with the engine running and revving up the battery shows 14-15 volts , any ideas thanks

 

[telectrix]

so the alternator's OK then. i'd be looking for a bad earth. maybe from engine block to body. stick an ohm meter across it.

 

[PEG]

Could also be the charge warning circuit,seperate to it's output,or any one of twenty other things...electrics on these are legendary. CanBus systems manage to complicate otherwise basic issues,and don't rely on code reading to ease the repair journey,at best it's a good hint and not a definative answer. Certainly you may get to miss the old escorts and vivas...

 

[applemac]

I had this on my van, corroded small wire that came out of alternator, put a new length in and problem solved.

 

[jimmymac]

Some of the diesel models have a clutched pulley on the alternator. If this fails it will cause an intermittent fault. One day it will be fine, the next day the light will be on. Has the battery been checked with a drop tester?

 

[UNG]

Do a google search "over-run alternator pulley" you should find the answer to your brothers problem

 

[iamelectric]

Some of the diesel models have a clutched pulley on the alternator. If this fails it will cause an intermittent fault. One day it will be fine, the next day the light will be on. Has the battery been checked with a drop tester?

no it hasn't

 

[jimmymac]

no it hasn't

It could be a faulty battery, any idea how old the battery is? If the battery is not accepting a charge then the charging warning light will come on. Did the battery get fully charged before be put into service with the replacement alternator?