Peugeot 405 Headlights

BuckTarbrush · Post by **BuckTarbrush** » 24 Jun 2006, 11:41

HELP !!!

I hope somebody out there can help me,

I have a problem with my Peugeot 405 sri(1991)at the moment, I have lost dipped beam ! This started as an intermitent problem for a few months and now i have no dip at all. Side lights and main beam work fine, I've checked the earth contacts, changed the bulbs and the relays, i've even changed the stalk on the steering column. Please halp as this is driving me mad.

Thanks in advance for any help.

AndersDK · Post by **AndersDK** » 24 Jun 2006, 19:29

you have changed/replaced quite a lot of bits -

Why dont you go by logic fault tracing ?
That would usually trace down the problem area within a few minutes - and it wont cost you a complete spares car to swap everything you suspect.

You know for a fact that to make a bulb lighting up - it will need chassis earth one side - and +12V the other side.
Then trace back from the bulb until you find both.
Or vice-versa : trace forth from the lights switch until you find where the +12V disappears ...

Note that the lights switch could also be missing a +12V feed.

BuckTarbrush · Post by **BuckTarbrush** » 24 Jun 2006, 20:14

Thank you for your post, Surely if there was no 12v feed, the main bean light wouldnt work as it is a H4 twin element bulb ??

AndersDK · Post by **AndersDK** » 24 Jun 2006, 22:54

BuckTarbrush wrote:Thank you for your post, Surely if there was no 12v feed, the main bean light wouldnt work as it is a H4 twin element bulb ??

Why not ?

There is absolutely no guarantee the dipped would get a +12V - just because the main circuit gets it. It depends purely on how the +12V feeds to the lights switch are made ...

Be patient - using a standard +12V test bulb w/ needle point & crocodile earth clamp - you can trace all kinds of lights problem in a car.
Take notes as you progress - not to go over the same tracing 3-10 times. Also use your notes to logically exclude problem areas - and to deduct possible untested areas of the circuit.

Note : you must of course have the dipped ligths engaged on the lights switch - to trace this circuit.
Be careful ! Lights circuits are rarely fused ! Its easy to set off a fire by a shortcircuit !

Possible problem you may find is a burned out wire - because its chafed and then shortcircuits to chassis earth.
Or a wire disrupted because of mechanical stress - or corrosion.
Both types of faults would have the nature like your description of the symptom.

PowerLee · Post by **PowerLee** » 24 Jun 2006, 23:57

405 lights are fused left & right, So its either the switch, the dim / dip resistor or the dim / dip headlamp relay.