hi,
Fiat Punto 1.2 petrol w reg year 2000 has apparent varying light brightness
to headlights and interior lights.
when stationary and rev engine lights tend to brighten then dim. this
applies also to interior lights. When driving along the road in darkness,
the lights tend to vary in brightness.
any ideas ?
Steve for a friend.

In article , Steve
says...

hi,
Fiat Punto 1.2 petrol w reg year 2000 has apparent varying light brightness
to headlights and interior lights.
when stationary and rev engine lights tend to brighten then dim. this
applies also to interior lights. When driving along the road in darkness,
the lights tend to vary in brightness.
any ideas ?
Steve for a friend.

Yep. Its working properly. When you rev the engine, the alternator
provides more current and a raise in voltage which results in brighter
lights although when driving down the road it shouldn't be massively
noticable.

Get the alternator tested.

--
Conor

I'm not prejudiced. I hate everybody equally.

On 06/02/2010 00:55, Steve wrote:
hi,
Fiat Punto 1.2 petrol w reg year 2000 has apparent varying light brightness
to headlights and interior lights.
when stationary and rev engine lights tend to brighten then dim. this
applies also to interior lights. When driving along the road in darkness,
the lights tend to vary in brightness.
any ideas ?
Steve for a friend.



If the battery's about had it this can happen. It's because it's not
good enough to light the lights at full strength by itself and you only
get full strength when the engine's going fast enough to get the
alternator to supply the required power. Suggest you get it checked.

Rob Graham

In article ,
Steve wrote:
hi, Fiat Punto 1.2 petrol w reg year 2000 has apparent varying light
brightness to headlights and interior lights. when stationary and rev
engine lights tend to brighten then dim. this applies also to interior
lights. When driving along the road in darkness, the lights tend to
vary in brightness. any ideas ?

Get a DVM and measure the voltage at the battery (lights on) at idle and
with the engine running faster so the lights are at their brightest and
report back. Some variation in brightness could be normal on that model.
But that could be proved by knowing the voltages are within tolerance.

You could also try charging the battery with an external charger and see
if the difference between bright and dim is still the same.

When actually moving, I'd not expect to see any variation in the lights.
Alternators tend to reach their peak output at quite low revs.

--
*Beware - animal lover - brakes for pussy*

Dave Plowman London SW
To e-mail, change noise into sound.

Steve wrote:
hi,
Fiat Punto 1.2 petrol w reg year 2000 has apparent varying light brightness
to headlights and interior lights.
when stationary and rev engine lights tend to brighten then dim. this
applies also to interior lights. When driving along the road in darkness,
the lights tend to vary in brightness.
any ideas ?
Steve for a friend.


It will do that to some degree normally, but if it varies greatly I'd
suspect the alternator or the regulator contained in it.

After serious thinking Steve wrote :
hi,
Fiat Punto 1.2 petrol w reg year 2000 has apparent varying light brightness
to headlights and interior lights.
when stationary and rev engine lights tend to brighten then dim. this applies
also to interior lights. When driving along the road in darkness, the lights
tend to vary in brightness.
any ideas ?
Steve for a friend.

If the alternator is under a heavy load, the voltage will drop a bit at
tick over and the lights dim a little. If at normal road speeds they
are varying, there is a fault on the alternator which needs to be
checked out - it could mean a rectifier has failed or the voltage
regulator.

--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk

Hi folk,
Many thanks for the replies, he had the alternator checked out with gauge
following advice and yes, the voltage regulator was a duffer, readings up
and down, and now stable after the fix. He replaced the alternator and as
the regulator was with it, got the fix that way.
Also replaced cambelt whilst at it as a wise move and it goes far better
now.

Steve


"Harry Bloomfield" wrote in message
. uk...
After serious thinking Steve wrote :
hi,
Fiat Punto 1.2 petrol w reg year 2000 has apparent varying light
brightness to headlights and interior lights.
when stationary and rev engine lights tend to brighten then dim. this
applies also to interior lights. When driving along the road in darkness,
the lights tend to vary in brightness.
any ideas ?
Steve for a friend.

If the alternator is under a heavy load, the voltage will drop a bit at
tick over and the lights dim a little. If at normal road speeds they are
varying, there is a fault on the alternator which needs to be checked
out - it could mean a rectifier has failed or the voltage regulator.

--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk