Pre Mot Test

[jord294 94]

Just prepping 405 for mot, and found an electrical issue.

 

Hope someone can help ??

 

Basically, all lights work perfect when car is not running. But once I start the car, the main beam bulb lights up slightly, so is on with sidelights.

 

Even with full beam, the sidelights are on when they should be off.

 

I've checked and cleaned connections and earth points.

 

Perhaps an alternator issue or switch fault????

 

I have no idea, so any guidance appreciated

[TooMany2cvs 65]

Does it have dimdip? What happens if you unplug the resistor for that?

[Davy 18 1 Cars]

If they're working as expected when the cars not running, then I'd quess the switch is working ok.

 

Are you sure it's not the 'dimmed dip' coming on? Thats the dipped beam part of the bulb glowing slightly? If so then thats normal I believe for when the ignition is turned on / car running?

[TooMany2cvs 65]

Davy - dimdip should put the dip beam on low when the ignition _and_ sidelights are on. Jord's problem is even when the sidies are off, so whatever's happening, it ain't right. I'm wondering if there's a failed diode or relay or electric-thingy in the dimdip system that's feeding back ignition live into the sidelight (and dim-dip) circuit.

[jord294 94]

Was always led to believe it's sidelights, then sidelights with main beam, then main beam and full beam with no sidelights.

 

But my sidelights are on on full beam.

 

All the above is how my car is.

 

Once I turn on the ignition, that's when I get an issue.

 

I'll check resistor again

[welshpug 1,666]

Main is full, i guess you mean dipped.

 

Ill check what my brothers 405 does, however it should be the same as a 205,

 

ignition off:

 

sidelights, dipped, main

 

Ignition on:

 

Dim dip, dip and sidelights, main beam. With sides iirc.

[TooMany2cvs 65]

Sides are always on with main & dip, ignition on or off.

 

The only difference with dimdip is that you don't have side-only with ignition on, that's replaced with side-plus-dimmed-dip. (there's a clue in the name... <grin>)

[jord294 94]

Thanks for input guys.

 

If you could check your brothers 405 mei, it would be appreciated

 

Sounds like I could be worrying about nothing

[farmer 328 1 Cars]

Andy, if needed I have the new resistor as I discussed last week on the telephone.

 

If needed will drop one off in the post to you.

[jord294 94]

Does it have dimdip? What happens if you unplug the resistor for that?

What exactly does the resistor do ?????

 

Have disconnected it, and lights work as they should.

 

That's with car running and not

[welshpug 1,666]

when you turn the sidelights on your dipped beam will come on at 20% power with the ignition on.

 

I would imagine if they're still working as intended, that you are unplugging the cooling fan resistor...

[TooMany2cvs 65]

What exactly does the resistor do ?????

It reduces the electricity being sent to the dip beam filament when the ignition and sidelights are on.

 

Have disconnected it, and lights work as they should.

Can we just recap?

 

With it in place...

Ignition on, LIGHT SWITCH OFF - side & dim-dip on?

Without it in place...

Ignition on, LIGHT SWITCH OFF - nothing on?

 

The way dim-dip should work...

Ignition on, lights on side - side & dim-dip

Ignition off, lights on side - side only

 

What you'll have now if you did pull the right relay...

Ignition on, lights on side - side only

Ignition off, lights on side - side only

 

If so, then that just confirms you've got a prob in the dim-dip. Honestly? I'd just bin the resistor. Dim-Dip was a legal requirement on new cars in the UK for a couple of years around the late '80s, early '90s. It's not been required since. It doesn't have to work even if fitted when the car was new. It was never required on new cars anywhere outside the UK, and isn't required to be fitted if you import one. It isn't tested at the MOT. Ignore it.

[jord294 94]

when you turn the sidelights on your dipped beam will come on at 20% power with the ignition on.

 

I would imagine if they're still working as intended, that you are unplugging the cooling fan resistor...

Is that how your brothers car is mei? As that is how my car is.

 

It's only when ignition off I get sidelights only. Then on dip I get sidelights aswell

 

Sounds like there isn't anything wrong with my car after all :rolleyes

[welshpug 1,666]

yeah, nowt wrong at all by the sounds of it

[jord294 94]

brilliant!

 

happy days

 

thanks for everyones input

[jord294 94]

Toomany2cvs

 

Thanks for the more in depth info.

 

I'll probably leave the resistor dis-connected, even though I know it works as it should.

 

I've had a few peugeots over the years, and the 405 is the only car I noticed the issue on

 

Cheers

[jackherer 543]

I've had a few peugeots over the years, and the 405 is the only car I noticed the issue on

 

It sounds like it's the first one you've had that actually works properly

 

It's not a surprise really, the wiring on old Peugeots was tarnished and corroded by ten years old, these days it's amazing any of it works at all.

[jord294 94]

 

It sounds like it's the first one you've had that actually works properly

 

It's not a surprise really, the wiring on old Peugeots was tarnished and corroded by ten years old, these days it's amazing any of it works at all.

 

you're probably right

[welshpug 1,666]

had a look at my brothers 405 this morning just before dropping it off for MOT, sides are on with each click.

 

so if a headlamp bulb goes down you still have a 5watt glow

[jord294 94]

thanks mei

 

that is how mine worked, but have kept resistor unplugged for now

[welshpug 1,666]

make sure its not the fan resistor

[jord294 94]

make sure its not the fan resistor

 

it's not. it's definitely the one for the lights.