Halogen headlight wiring....

[shaunroche]

Just when I thought I was getting somewhere with the wiring, I decide to open the box with the new headlights I've had for about 18 months and pop them in today.....well I should have known it would never be that simple!!

I thought it would be a simple case of fitting the lights and fitting the plugs...Ha!

Obviously, we know that the main beam connectors have two pin plugs and the dipped beam lights three pin plugs, as the dipped light unit obviously has a dipped and main beam capability.

I've sketched below what I have in the loom....the standard dipped head light connector has white and blue, red and blue and a black wire....the nearside connector single wires, the offside two red and blue but clearly, only three pins in each connector. The two outer plugs are both white and blue and a black earth.

The new lights, both inner and outer are 55W, the outer unit has a bulb with three spades and a separate side light bulb; the inner has two spades.

So, question: how and earth do I wire them up so that they act the same as standard Dolomite headlights? I'm really confused as to how I get three into two etc.!

I did a bit of preliminary wiring and had bulbs coming on when on when it was on dipped and then when on full beam, some bulbs going off and some coming on.....so, appreciate it's not quite as straight forward as thought!

I imagine that the outer (3 plug) needs additional wires linked to the dipped circuit so that it will come on when the dipped is on, but just not sure!

If it's all obvious, then fair enough, but at least I do feel as though I'm coming on here and keeping people amused with my moronic questions!



Ps - as the bulbs are only 55W, I assume I don't need to add relays?

[tony g]

The outer 3 pin will fit just the same as before. Straight on no mods needed. On the inners, if your lamps have a clip in adapter for the single wire bulb an easy way is to remove the adapter thing and fit a 3 prong build in the same way as the outers. Then your 2 pin plug for the original inners will fit straight on as before, albeit with the 3rd terminal not being used. The one not being used is simply the dip beam that the inners dont use (but the outers do).
Failing all that the inners will need the + feed cut from the standard plug and fitted to the bulb and the other one from your plug to the earth connection supplied.

Advantage of using a new H4 3 terminal bulb in the inners is if one of your outer dip beam blows you can swap it for an inner one cos the dip hasnt been used plus the main beam will still work on the other bulb you removed from the outer.
Hope that makes sense Im sober

Tony

[Toledo Man]

The relays are essential not so much for the bulbs but to prevent your indicator stalk from burning out. They take the load off the rest of the lighting circuit. I know you've fitted a new loom but do you really want to find out the hard way?

[shaunroche]

Ah! This confusion all revolves around the fact that I didn't realise that the outer plug was three pin as standard as there wasn't one on my assy that I put together 18 months ago!

I've jut had a root round in the garage and found a three pin socket that must have come off the car when I first started it and notice that the wires are UW, UR & B....I didn't realise the outers were three pin as standard....I was seduced by the two pin socket (UW and B) that came with the loom and then confused by the three pin socket with the UR etc., thinking that they were the inners.......I'm not very bright (no pun intended) but certainly grateful when the penny drops!

Cheers Tony, that's another one I owe you!

[tony g]

No problem Im having a pint now so ignore anything else I say

Tony

[shaunroche]

The relays are essential not so much for the bulbs but to prevent your indicator stalk from burning out. They take the load off the rest of the lighting circuit. I know you've fitted a new loom but do you really want to find out the hard way?

Hehe, good point well made...I have the relays etc. ready to fit, so I'll continue with the original plan...cheers!