Battery light

[escortmad4eva]

Hi guys i have got a problem with my battery light it only comes on very dim when i have the lights on wipers heater and de mist rear screen underload so i replaced the alternater and battery with brand new parts and the battery is charging at 14.3 volts what else could this be? but at night its really annoying me!! any help i would be very greatfull

[dave waudby]

beleive me on this one i do know what im ion about as ive done it twice because dim battery lights annoy me

 

you need to fit a diode into the wire which comes from your alternater to the battery light

 

a diode must be fitted the right way round, it is because your wiring loom is old and the current is trying to travel both ways the diode acts as a oneway filter and solves this problem

 

i fitted the one below (see the link) i chopped the diode out (black part of the yellow wire) and keeping it the correct way round (from the plug to the loom) snipped my wire feeding the battery light and fitted the diode in, problem solved

 

done it twice once on a pinto s i e r r a once on my pinto cortina

 

http://cgi.ebay.com/ebaymotors/Delco-10 ... ccessories

 

hope this helps

[escortmad4eva]

Now at least i can try that so i can sort this so i need to locate the orginal diode cut it out and replace? have you got a bit more detail? cheers

[dave waudby]

no just fit a diode in line

 

the ones he sells are fine and that way you know youve fitted it correct way round (from plug going into your loom

 

i fitted mine about 2 inches from the alternater plug

the only chopping is snip the wire to fit the diode

 

what car/ engine you got ??

[escortmad4eva]

In the pic it shows a white plug, is that what i get just still a bit confused abit mate so one wire goes to the positive on alternater the chop in on the loom to the batt light? wheres the plug go?

[dave waudby]

i didnt use the white plug

 

i used exactally what was on my car already

 

all i did was snip (in my case the thin blue wire) which came out of my alternater plug)

 

then from the new loom sniped the diode out and connected it in line to my blue wire

 

threw the rest in the bin

 

(but make sure you keep the diode the same way round as it comes off his loom as its like a valve)

[Savvi]

Dave does the warning light still come on when you go to start etc.

 

 

This type of fault is normally down to poor connections, bad earth's or a battery or alternator failing.

 

The warning light is to give you an indication of whether the charging is working or not.

 

By fitting a diode you are stopping current from flowing in both directions, on some alternators they need a signal to start the charging process on others they don't.

I'm intested to hear how this will work as you will making the current to flow in only one direction via the warning light (blue) wire.

[dave waudby]

Dave does the warning light still come on when you go to start etc.

 

 

This type of fault is normally down to poor connections, bad earth's or a battery or alternator failing.

 

The warning light is to give you an indication of whether the charging is working or not.

 

By fitting a diode you are stopping current from flowing in both directions, on some alternators they need a signal to start the charging process on others they don't.

I'm intested to hear how this will work as you will making the current to flow in only one direction via the warning light (blue) wire.

 

i only knew about this as a fully quallified auto electrician showed me

 

yes my battery light works as it should comes on with ignition etc

 

i tried everything on my cortina even borrowed parts from another mk5 cortina (which was in full working condition)

 

tried new batteries alternaters, got alternaters tested etc

 

multi meter testing every thig and all earths connections checked cleaned tightened, still my battery light lit dimly

 

so went down the diode route that was shown to me a few years ago with my s i e r r a and its fine now

 

did it very early this year no problems since

[Savvi]

I'm guessing that if a fault ocuured within the alternator then the warning light would not come on when engine running which it would normally do.

 

 

What you have done will cure the fault so as long as you bear in mind that if it stops charging when out driving you will have no warning light it will be fine to do what Dave has done.

 

You can buy a diode from maplins for a few pence, you would need a large one though

[moredoorAsh]

This is interesting as i have the same problem.

 

Its only visable at night when the lights are on and the bat light only iluminates vey dim.

 

When i give it some the light goes off but as soon as i back off its back on again.

 

I've only driven it at night twice since june so its not that big an issue for me

 

Would be handy to know a cure though.

 

Oh my alternator is brand-new also

[dave waudby]

savvi may well be right saying the battery light will not come on if your charging system fails

 

i dont know

 

but all i know is my battery light being on dim pissed me off, and my battery charges fully the battery light lights with the ignition on so im happy

[cjay2004]

my mate had this problem, he just cleaned all the connections + fuses & there connections & the problem went away...

but im not says that will cure all cases???