Car headlights oddness

[scottmk1]

Right I'm looking into this again and someone has put a component in one of the wires going to the headlight bulbs, same on both sides. Any idea why it's been added? Garbage job on the soldering too!

 

[Hood]

It is a diode but why it is there I don't know.

 

[scottmk1]

I wasn't sure exactly what it was, and my electrickery knowledge isn't the best.

 

[Hood]

Well it allows current to flow in one direction but not the other so is often used to stop back feeding but without seeing how it connects into the circuit I have no idea what it is there for.

 

[scottmk1]

It's a live feed to the headlight bulbs. Reads 12v to earth with both dipped and full beam on. If you were looking at the back of the bulb, that wire connects to the right hand terminal.

 

[zx9]

It's a live feed to the headlight bulbs. Reads 12v to earth with both dipped and full beam on. If you were looking at the back of the bulb, that wire connects to the right hand terminal.

An attempt at stopping back currents rather than cleaning up earth connections and lamp holder contacts, take it out and enjoy the light show.
I imagine the headlights or rear lights will dim in phase with the indicators / stop lights, something like that.

 

[scottmk1]

I've removed them but it's not changed anything. Just going to start hunting earths and clean up any that I find

 

[bricol]

Has it got, or had, an aftermarket HID conversion for a dual filament bulb? Such as H4 - main and dip in the same bulb?

A kit that I have in my old 106 has an electromagnet inside that pulled the HID "bulb" back into the main beam position - the diode was somewhere in circuit to keep power to the control unit for the "bulb" when you pulled main beam as the dual filament halogen original would switch off the dip as you went to main.

I rejigged the wiring to use two hella lamps on the bumper as main beam instead.

 

[Olderisbetter]

I have seen Diodes used before in LED conversions to stop the car sensing a blown bulb

 

[scottmk1]

It's got H4 bulbs but not HID, just the normal dual filament type.

 

[jsf55]

The rally guys used to wire relays in to get both main and dipped on when main beam was operated, I wonder if this is a cheaper version of that ??

 

[scottmk1]

It could be but I can't see anything to tell me that's what has been done.

 

[earthman]

i had a similar problem caused by a faulty bulb putting dip and main on together
remove one bulb then try it same with the other one

Not often you get a faulty made bulb but I have experienced that once myself, it were a twin filament bulb for the rear of a van.

 

[scottmk1]

I'll give that a go tomorrow.

 

[8ob]

Looks like some kind of get around/bodge for DRL`s.

Bob

 

[scottmk1]

Not sure about the DRL theory, when the lights are switched off they are all off, it's just the main/dipped function is **** about face

 

[angellonewolf]

how old is the car can you not remove the connections in the stalk so it just swaps it round the right way ?

and as from earler clean all earths as that wouls be a good reason why the diode is there but not sure its the reason the lights are swaped

 

[scottmk1]

I've looked at the stalk and it doesn't appear to have been messed with there. I will take another look tomorrow as I still have the cowl off the column

 

[angellonewolf]

could you if there are 2 pins that can be swaped so it works as should or 2 sets of butlet connectors after the plug in there wiring that swaps the 2 wires switching the main beam and the high beam ?

 

[Melvyn Best]

I’ve had problems with some Japanese car headlights that have a live feed to the common connection on the bulb with the other connections being earthed by the dip switch , sometimes via a change over relay. A bit of abode but possibly the easiest way of sorting the problem might be to just swap the wires on the bulb connector as already suggested?