> I 'think' the Headlights work through the Ignition switch, and that the
> contacts in there sometimes corrode/break down, so you might like to check
[quoted text clipped - 3 lines]
>
> Graham
I can confirm that the headlight and tail light current
(which is quite substantial) goes through the ignition switch, so that the
headlights go off wnen the ignition is off. Worse, to this current is added
things like heater fan, wipers, rear screen heater - all of which push up
the amps. The push on quarter in tab carrying this load, not to mention
the ignition switch itself starts to cook and the switch block on the end
of the ignition switch turns brown and starts to char. Both Mk1 and Mk2
Unos are prone to this, particularly if you drive mostly at night, when
everything is on.
Having had total failure on the motorway in conditions that needed wipers
and heater I was not well pleased when all the lights etc went out. Not
to mention this could be lethal if there was a HGV on your tail.
It's not a roadside fix, you need to get the steering wheel shroud off,
plus have a replacement switch to hand. With a bit of luck you may be
able to swap just the contact block. Replacing the ignition switch
is a pain in the arse due to it being fixed with break head bolts. I
can't imagine why, no joy rider is going to the trouble of removing
it.
Lets hope you only have an earthing problem. You might also
check the fuses and fuse box.
Mark Garner - 11 Dec 2003 11:16 GMT
> > I 'think' the Headlights work through the Ignition switch, and that the
> > contacts in there sometimes corrode/break down, so you might like to check
[quoted text clipped - 27 lines]
> Lets hope you only have an earthing problem. You might also
> check the fuses and fuse box.
Thats interesting to know, at least I now know I'm not looking for a
relay hidden somewhere inacessible. I had also considered it could be a
problem with the the headlamp stalk itself, but I couldn't see why a
problem with that switch would take out everything, including main beam
and flash etc.
The car is the girlfriends, and she has a tendancy to leave the lights
on and turn everything off at the ignition, then restart the car in the
same way. I can't see that being helpful in this situation. This
actually explains something odd I found when I was trying to fix it -
I'd turn the car off, check the fuses, nothing would be wrong, I'd turn
the ignition on again, and it would work again - it looks like the
switch. I assume that not fitting a relay in this circuit was a cost
option for fiat.
Anyway, Nothing will be done to it till the weekend then its grab the
DVM and then, recheck the fuses and then check the earths. Then if no
joy remove the steering shroud to check the ignition switch and the
condition of the connectors.
Luckily it's parked outside her house, so there not a problem in working
on the car, unluckily she's got mine to drive round in whilst her's
can't be driven (don't ask how that happened).
Anyway, thanks for the info, I'll let you know what happens...........
Mark
Brian Sandle - 12 Dec 2003 11:20 GMT
In alt.autos.fiat Mark Garner <mark.garner@durham.ac.uk> wrote:
> The car is the girlfriends, and she has a tendancy to leave the lights
> on and turn everything off at the ignition, then restart the car in the
> same way.
Having blown two headlamps that way I remember to turn the headlamps off
before starting.
Also around town the headlamps are more for other vehicles to see, and I
have gone down to non-halogen ones which do use a lot less current. I do
not think they dazzle oncoming drivers so much, either. Then, too, I think
the battery will stay in better condition, as the current drain to halogen
lamps must reduce the voltage to charge the battery in mainly night
driving.
Jasper Janssen - 19 Dec 2003 13:38 GMT
>Having blown two headlamps that way I remember to turn the headlamps off
>before starting.
My mom used to do that, it took a dozen or maybe two headlamps to figure
out why they were blowing so often.
Jasper
Paul Long - 11 Dec 2003 14:24 GMT
> Lets hope you only have an earthing problem. You might also
> check the fuses and fuse box.
If I could add my 2p worth...............
I had a similar problem with an Uno 45 where the headlight main beam would
work fine one minute and fail totally the next.
Replacing fuses etc had no effect.
I eventually traced the fault to the fuse board itself - I discovered that
waggling the connector blocks to the board miraculously made them work
again.
Tracked one down at a scrapyard, swapped it and it's been fine ever since.
(touch wood etc. etc.)
I took the old board to pieces and examined it but there was nothing to see
visually. Possibly a fractured printed circuit track?
HTH
Paul
Pete Smith - 11 Dec 2003 15:09 GMT
> > Lets hope you only have an earthing problem. You might also
> > check the fuses and fuse box.
[quoted text clipped - 15 lines]
> I took the old board to pieces and examined it but there was nothing to see
> visually. Possibly a fractured printed circuit track?
IME, things like this go where the solder meets the contacts on the back of
the fuse holder.
They _appear_ to be OK, but sometimes there'll be a tiny black line between
the solder and contact.
This is called a Dry Joint.
Normally getting a soldering iron and going through all the solder, melting
it, causing it to re-attach to the connector is enough.
Pete.

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