Headlamp Wiring

[Guest Mr Pid]

After fitting lamps supplied by RHE, and attempting to wire them up, no matter what configuration of wires i use i cant seeme to get the buggers to light up.

 

Ive tried passing a current directly through each lamp individually independant of the power supply from the car but still doesnt work!

 

I'm using the sierra loom in all its glory- What is the best route forward?

 

Any help much appreciated.

 

Stu

[Big Jim]

If you look square on at the 3 terminals on the headlight bulb, think of them as an 'n' shape. The horizontal one at the top is the dip beam feed, the one on the left is earth, and the one on the right is main beam feed. Now find out which wire the current is coming up when each application is switched on, and there you have it. If it doesn't work then, you've got problems elsewhere.

[Guest Taffy Rob]

Hi

when you tried an alternate power source, Im assuming you ran the earth back to the power source and not the car? Daft question I know but you never know

Try this with the configuration Jim has stated, if it doesnt work at all then the only possible explanation is that the sealed beam units are dodgy - I had one from rhe but luckily kept the ones off the mini I took the the side lamp mounts from. They are sensitive chaps and can get damaged in transit, or even from storage conditions if kept somewhere (for example) very damp over a long space of time.

Rob

[Guest Ant]

Using the lead which comes with the RHE units I think the black is earth, the green is 12v for the dip beam, and the red is 12v for the main beam. Try that directly to a battery (make sure the battery is ok with a different bulb). If that works then get a multimeter onto the ends of the loom wiring and go from there.

 

Have you modified the loom at all by removing the lamp failure unit (if you had one)?

 

Ant

[Les Welsher]

I had this problem when I tried to connect up my headlights, I tried to get them to work by touching the relevent wires one at a time but all I could get to work were the side lights.

I then read an e-mail from someone about an extra earth wire for the dim dip on the drivers side going through relays.

I connected everything up then tried them and they all worked, it seems they had to be connected for the relays to kick in.

 

Here is a copy of that mail for the drivers headlight.

 

Brown - Earth - for sidelight

Grey and red - Side light - power for sidelight

Yellow - Dip beam - power for dip beam

White - Main beam - power for main beam

Blue Green - earth from headlight - to dim dip relay (Item 34) connection 38. This is then gives an

earth through 87A when ignition on and dip or main beam are selected, (power

from fuses 1 & 2 or 3 & 4). Or 12 volts from fuse 17 when sidelights selected

and then finds its earth through the otherside dip beam ( 2 bulbs in series

hence dim dip).

 

Hope this helps

 

Les

[Guest SteveL]

Hi Stu

 

I'm assuming that you've tested the headlights by connecting them directly to the battery, to test that they're working okay?

 

I had a right job getting my lights to work properly. Take a look at my build diary, specifically August 28th onwards. The colours of the wires are all detailed there, and even though I use a different headlight (so different coloured wires) it should help you out.

 

As Les said, the wiring on the drivers side headlight is different to the passenger side. There is no conventional earth connection, but the wire from the drivers headlight earth connects to a blue/green wire. This wire goes to terminal 30 on Dip/Dip Relay II. Depending on the presence of current flowing through terminals 85 and 86 on this relay, terminal 30 is either connected to terminal 87 or 87A. Terminal 87 is connected via a black/red wire to fuse 17. Terminal 87A is connected directly to earth. Because of this, all the wires need to be connected to get the lights to work properly.

 

When the connection is to terminal 87, the current flows through the drivers headlight and then through the passenger headlight and then to earth. 12V across two bulbs in series gives 6V at each buld, hence the dim of dim/dip.

 

When the connection is to terminal 87A, the current flows directly to earth. Each bulb receives 12V, the dip of dim/dip.

 

What caught me out was that for this to work, both screws which hold the right hand column stalk in place need to be screwed in, as the bottom one gives you an earth. WIthout this, you'll never get dipped beam, only dim.

 

Steve

 

PS. Don't forget that the RHE headlights don't have sidelights included, and sidelights are neccessary to get through the MOT. That's one of the reasons I bought two new headlights (H4 bulbs plus sidelights).

[Guest Mr Pid]

Cheers chaps,

 

I did try them directly onto the battery but to no avail, i have a new heavy duty battery now so i shall try this then check all the wiring configurations.

 

Thanks for all the info, just need to get my engine fixed now.

 

Stu