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Old 14-01-2019, 09:11 PM
Grease Monkey's Avatar
Grease Monkey Grease Monkey is offline
Join Date: Dec 2009
Location: UK
Posts: 51
Angry L200 head light fault

Hi looking for a little help, 55 plate L200.

First noted condensation in off/side head light, and then a day or so later the dip beam had gone, simple yeah well.....

So we thought, bulb out H4 as I remember, and yeah dip filament in the bulb had gone, easy fix, you would think, but no.

New bulb fitted right one H4 12 volt, switch on dip within seconds the bulb is smoking and about to blow, looks like the two bulb fillements in the bulb were on.

Check 3 pin bulb plug with meter and Led volt probe, dip lights on and two 12v feeds noted and no ground or the ground was 12v too, I know the one outside pin of the H4 bulb is the ground, from what I think the cable there is red blue.

I try adding a ground to get a repair as I don't have a circ dia: to work from, if you try adding a ground, there is high current sparks and clicking sounds going on, this would say to me there is some kind of can network or head light controller running the lights?

What I ask is if so where is it, or has anyone seen this fault before, is it a common fault with a 55 plate truck, or any ideas.

The wire colors at the 3 pin headlight plug are red outer pin to the off/side, red blue outer pin to the near/side, red white on the top pin, looking into the the rear of the H4 bulb.

I do see what look like relays for the lights in the bonnet bay fuse box.

Thank you for any help you can give Grease Monkey
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Old 14-01-2019, 10:18 PM
Bob the Boss's Avatar
Bob the Boss Bob the Boss is offline
Join Date: Oct 2009
Location: Madley in Herefordshire Uk.
Posts: 663

Hi, seen this before, the polarity changes with each setting.

check the dim dip relay unplug if need be.
Then check the 3 relays on the inner wing behind battery.

The damp gets in the headlamp from the heat of the bulb, blow it out with an air gun on an air line throw the hole for the bulb, if it's still in there.
Gibbins Motors Technology Uk
The more you know the less you know!!
Bob the Boss forum owner
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Old 22-02-2019, 02:22 PM
Grease Monkey's Avatar
Grease Monkey Grease Monkey is offline
Join Date: Dec 2009
Location: UK
Posts: 51

Thank you, the relay was the fault
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Old 22-02-2019, 07:26 PM
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Holly Goodhead Holly Goodhead is offline
Join Date: Oct 2016
Location: Hay-on-Wye in Wales
Posts: 3,997

Thank you for letting us know
, you may be,
But now Kembles Thertre Usherette
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