0

0writer

Member

• Sep 29, 2012

• #1

Afternoon all,

The battery light is lit up on my dash, nice and bright.

I needed a new battery anyway so that has been replaced in the last week but the light was still on. I knew the tensioner bearing needed doing so have done that today along with fitting a new belt but the light is still on. I get 12.5v when off and 14.7v when running across the battery.

Any ideas?

 

blue beasty

Leaks an prone to bits dropping off

• Sep 29, 2012

• #2

Warning light wire connection on the back of the alternator. The light only goes out when the voltage from this wire is more than the battery voltage.

 

0

0writer

Member

• Sep 29, 2012

• #3

Thanks for the quick reply, sounds like I need to check the wiring is clean and tight at the back of the alternator.

 

R

ruffday

Active Member

• Sep 29, 2012

• #4

I could be wrong but 14.7v sounds a bit high to me.
Could be overcharging.

 

Freediscoranger

Active Member

• Sep 29, 2012

• #5

charging system should produce 14.2V +- 0.2 V

 

alex8882

Well-Known Member

• Sep 30, 2012

• #6

my alty normally puts out around 14.4v when charging

 

0

0writer

Member

• Sep 30, 2012

• #7

Just double checked the numbers to be sure and the voltmeter is showing 12.46v not running and 14.78 running which does seem to high. Any other advice or should I buy a new alternator? When buying, does brand make a difference? Was thinking off going 100amp.

 

discool

Well-Known Member

• Sep 30, 2012

• #8

0writer said:

Just double checked the numbers to be sure and the voltmeter is showing 12.46v not running and 14.78 running which does seem to high. Any other advice or should I buy a new alternator? When buying, does brand make a difference? Was thinking off going 100amp.

Click to expand...

Don't worry about the standby voltage only the max when charging via the alternator is 14.4v.
As u can see on my meter my battey voltage was just 11.7v when I took the photo, and this meter is certified every year which states it has 2% +- variability so it's doubtfull at 14.4v if it would read that.
So much for a £220 multimeter.

 

Attachments

• 
  We have power 005.JPG

  239.7 KB · Views: 114

Last edited: Sep 30, 2012

0

0writer

Member

• Oct 6, 2012

• #9

Got the alternator off the car today and my neighbour saw me. He said that if it's overcharging it could be the regulator on the alternator and it's worth testing that as it's £10 to replace. Does anyone know how i can test the regulator?

 

discool

Well-Known Member

• Oct 6, 2012

• #10

You could have done a Google search on that.
Alternator & Charging System Checks (Alternator Testing)

 

0

0writer

Member

• Oct 6, 2012

• #11

But then I couldn't have thanked you for a great link (sorry, didn't think).

Thanks!

 

discool

Well-Known Member

• Oct 6, 2012

• #12

0writer said:

But then I couldn't have thanked you for a great link (sorry, didn't think).

Thanks!

Click to expand...

.... loads of info on that subject on the www and yes the diode pack is replacable but the wiring connections are fusion welded not screw, so you will have to cut and then use grimps not solder as that will/may melt with the high current, again, all info on the web :tea:

 

Last edited: Oct 6, 2012