Citroen AX 87 dimmed L headlight

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jsp
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Citroen AX 87 dimmed L headlight

Post by jsp »

So I just recently welded my AX 10E 1987 and after this I put my headlights back and one headlight is dimmed the other will burn?

Is there no relay between it?

Anyone knows this?

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xantia_v6
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Re: Citroen AX 87 dimmed L headlight

Post by xantia_v6 »

This is almost certainly a disconnected earth wire, or a corroded earthing point for the headlight.

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Re: Citroen AX 87 dimmed L headlight

Post by jsp »

Should I pull an extra wire earth then to the headlights?

I was rethinking redoing the whole light system.

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Re: Citroen AX 87 dimmed L headlight

Post by xantia_v6 »

You could just try running a new ground wire to the affected headlamp as a temporary repair.

Your wiring diagram is a bit confusing and as drawn, probably would not work.

Note the pin numbering on Bosch relays:

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It is probably just as good to fit a single pair of relays that feed both headlights, doubling up on the relays won't improve performance if suitable gauge wiring is used.

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Re: Citroen AX 87 dimmed L headlight

Post by white exec »

Agree with that. Only two relays needed: one for main beam, one for dipped.
This takes the electrical strain off the lighting/dip switch, and can keep cable runs from battery (fuse) to headlights short.

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Re: Citroen AX 87 dimmed L headlight

Post by jsp »

ok what is the pinout of a H4 lamp?

are the R2 and H4 pinout the same?

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Re: Citroen AX 87 dimmed L headlight

Post by white exec »

H4 bulb connections.JPG
H4 bulb connections.JPG (14.95 KiB) Viewed 51 times

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Re: Citroen AX 87 dimmed L headlight

Post by jsp »

Thank you for your reply,

Are these the earthing?

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Headlights :
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Re: Citroen AX 87 dimmed L headlight

Post by jsp »

ok just got sorted, broken dipped beam wire. Will rewire all with relays.

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Re: Citroen AX 87 dimmed L headlight

Post by white exec »

A missing earth/ground connection on an H4 puts both filaments in series, and finding a path back through the other headlight, so the faulty one appears exceptionally dim!

Missing earths on rear light clusters produce all sorts of fun, including indicator and tail-light bulbs dimming and glowing every time the brakes or indicators are used. Car manufacturers still seem to struggle with bodywork grounding. Hardly rocket-science, but it does involve Beans.

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Re: Citroen AX 87 dimmed L headlight

Post by jsp »

white exec wrote:
16 May 2020, 08:28
A missing earth/ground connection on an H4 puts both filaments in series, and finding a path back through the other headlight, so the faulty one appears exceptionally dim!

Missing earths on rear light clusters produce all sorts of fun, including indicator and tail-light bulbs dimming and glowing every time the brakes or indicators are used. Car manufacturers still seem to struggle with bodywork grounding. Hardly rocket-science, but it does involve Beans.
Thanks Exec, seems only German/French car struggle to do an extra earth on the rear lights.

Got it fixed now, will rewire all with relays.