battery light comes on when the headlights are turned on!

[CANEX]

I've just noticed that my battery light comes on when the headlights are turned on!!
Or when the headlights are flashed!
I have a volt meter plugged in the cigarette lighter & it is showing 11-12 volts when engine not running & 13-14.4 when it is - so it must be charging.
It doesn't come on with anything else - ie heated seats etc

any ideas anyone?

cheers
Chris

 

[frank rabbets]

Could still be the alternator plug at the rear of the alternator. The wires do more than just charge the battery. I don't know what exactly but worth cleaning them.

 

[t1pper]

Slipping fan belts under load??

 

[uHu]

First of all, measure the voltage directly on the battery terminals. You should have 14.4 with the engine running at a higher rev than idle, with or without the lights on.

 

[Giles]

hi there

i agree should be 14.4 at the batteries, could be the belt slipping, my car does the same when i drive it through floods.

if you have a battery charger leave the battery on overnight and check they are 13.2 when they come off..could just be it has become to flat or faulty for the alternator to charge properly. Alternators don,t charge very flat batteries well.

Giles

 

[CANEX]

Thanks for your replies,
there is definitely a charge as the voltage is 14+ when running, but the light wasn't coming on with anything else taking a load - so must be a fault with the headlights.

It has now gone off! so there must be a loose connection somewhere, I noticed it was flickering a few times last night while I was driving with no apparent reason but today
it hasn't come on at all - so far!

I'll have to wait & see if it comes back on & try to find the bad connection!

cheers
Chris

 

[Giles]

my bet is when the light is on you don`t have 14.4,,you may find its just the terminals in the pug have corroded and gone green in the back of the alternator and need some spray

 

[fridayman]

First thing to do is check and clean the battery terminal connections.