Xantia Mk 1: Which Headlamp bulbs?

Evodad · Post by **Evodad** » 06 Dec 2006, 17:41

I know there's been lots of posts on this subject, but.

Currently, what's the definitive headlamp bulb to use in my Xantia Mk1 to improve the lighting, Phillips, Osram, Halfords own brand or what?
I'm fed up of guessing where the kerb is on wet unlit roads. I'll get it wrong one day (or night)!

Thanks.

jeremy · Post by **jeremy** » 06 Dec 2006, 18:02

You won't derive any benefit from stronger bulbs unless

The headlamps are aligned properly

The power supply to the bulbs is improved by fitting heavier cables (with fuses) straight from the battery controlled by relays - controlled from the existing circuits. The earth is important as well.

There is also a cable running under the front of the Xantia in a nice split conduit - problem is that the split in the trunking can face upward in which case the trunking fills with nice salty water and corrodes the wires.

Just as an example if the resistance of the bulb is 3 ohms (which is quite close) the wattage at 13.5 volts will be 61 and at 12.5 volts it will be 52. This shows that the difference of one volt is about 20% in power consumed!

Sorry - bit more difficult than changing bulbs

Evodad · Post by **Evodad** » 06 Dec 2006, 18:28

Jeremy, thanks for the reply.

I reckon the alignment is correct because the car has just passed it's MOT.
I wasn't thinking of fitting higher wattage bulbs, I was thinking of "different" bulbs.

The ones in now I assume to be "standard" bulbs (whatever that means), I was thinking of the xenon or High output bulbs with the same wattage as the standard ones.

Does this post make sense?

Thanks,
Roy.

jeremy · Post by **jeremy** » 06 Dec 2006, 18:51

While an MOT test requires the car to be fitted to a beam testing machine - the machine is NOT used to align the lights - just to ensure that they don't dazzle. Citroen ones are often set too low anyway especially on cars without anti-sink as the engine has been turned off and the back sunk a little before the test is done.

The point is you are unlikely to be getting the full benefit from your standard bulbs - so you won't get the benefit from better ones.

MOT testers handbook here - has diagrams for light alignment but I think they are for the beamseter machine. Good guide is to point them at a fence with the car on level ground and see where the centres of the main beams are. They should be approx parallel to the ground or slightly down and slightly to the left. If they are correct they will take the dips with them. When I test them I put a coat over the light I'm not dealing with - and put tape on the fence at the centre of the main light unit. (Drive up to the fence, mark it and drive STRAIGHT back)

http://www.motuk.co.uk/welcome.htm

Post by **RichardW** » 06 Dec 2006, 19:41

I partly agree, and partly disagree with Jeremy. I use Phillips Vision Plus, and they are much better than the normal bulbs that came out. However, having said that I agree that you need to make sure you are getting the full voltage at the bulbs - but I think Xantia head lights are relayed anyway - I think when I checked mine I was getting >12V at them

Kowalski · Post by **Kowalski** » 07 Dec 2006, 14:00

I have Philips Vision Plus bulbs in my car and they did improve the dipped beams over the standard Philips bulbs that were fitted but the single thing that makes the biggest difference in my experience has been keeping the headlight lenses clean. If your lenses are dirty, the dirt stops the light, its as simple as that.

The connectors on the back of the headlights can get dirty and corroded and if your headlights are missing their back covers, the silver comes off the reflectors. Halogen bulbs degrade over time, some of the metal of the filament vapourises and you get a black residue on the inside of the glass, so if you've got old bulbs in your headlights it might be worth replacing them with newer ones if they look dirty inside.

I looked into replacing the Halogen bulbs with HiD Xenon bulbs, you can get the kits with a special bulb that goes into a normal headlight plus a balast to wire in somewhere, that'd be far more effective than wiring in a new relay....

Post by **RichardW** » 07 Dec 2006, 14:56

I was going to say HiD are v.expensiev retro fit - but there's a company knocking them out on e-bay at £80 - which seems not too bad to me! May well consider if for my next one.

Must take the glass off my lights and wash it inside - I've heard that the reflector is very delicate, so I think I'll just brush it out with a paint brush!

citronut · Post by **citronut** » 07 Dec 2006, 19:41

the beam aim is ment to be acurate after it has been set on an MOT stations beam setter,firstly if the tester knows how to use the equipment,and secondly if the suspension is on normal hight at both ends of the car
regards malcolm

AndersDK · Post by **AndersDK** » 08 Dec 2006, 16:46

Roy -

Go for the electric circuit update suggested by jeremy. You WILL be amazed on the difference in light output. No doubt. And that is with your old standard bulbs still fitted 8)
To convince yourself, turn on the engine, let idle, turn on the main lights, then have an assistant measure up the voltage DIRECTLY on the bulb terminals.
Compare with the voltage measured DIRECTLY on the battery poles.
The difference should be less than 0.5Volts.

THEN you put in the new generation +50 light output bulbs. Either Philips or Osram, or even the discount PowerBulbs offered. Once again you WILL be amazed - I promise

(these are standard wattage, but new technology Xenon gas bulbs)

Evodad · Post by **Evodad** » 09 Dec 2006, 23:15

Sorry to want nannying again, but where's the best place to break into the wiring loom to fit the relay modification?

Thanks,
Roy.

davetd · Post by **davetd** » 10 Dec 2006, 11:21

You don't need to.

The terminal on the back of your bulb at the moment is what you plug onto the relay so that the relay activates when you turn on your headlight switch.

I'm modding mine this morning

regards

davetd

dan_the_v8man · Post by **dan_the_v8man** » 12 Dec 2006, 00:01

so wheres a good place to hide the relays out of the way of the crap?

Evodad · Post by **Evodad** » 12 Dec 2006, 08:05

For the relay mod on dip say, would it be sufficient to take the feed to one of the headlights to connect to the coil side of the relay & leave the other one redundant?
Or would it be better to use both, being as the relay is going to supply both lights?

Thanks,
Roy.

jeremy · Post by **jeremy** » 12 Dec 2006, 09:36

Your circuit could be: Heavy wire from battery terminal to fuse unit to relay power inout (not coil) and from relay power output to headlamps. The relay only needs a tiny current to operate it so operating circuit - (coil) from existing dipped supply to earth via coil.

You have the opportunity to improve safety here. With the arrangement above if the fuse blows - both lamps go out. If you double up on the power wiring and relay you will provide an individual supply to both lamps. This could still be operated by the dipped feed to the most convenient light.

I think you will find there is in fact a single wire for both dipped lights from the switch and it simply divides at the first light unit. You will probably also find that the lighting supply is totally unfused! This is probably done for safety reasons - to avoid being plunged into darkness just beacause a fuse blows.

I would recommend the 2 fuse/relay system as its unlikely that both circuits will blow a fuse at the same time. Fuses should be at least 2 x the likely consumption of the circuit. The wires should be thick and decent terminals etc used throughout. A convenient way of picking up a supply is to use a ring terminal and bolt it under the battery terminal securing bolt.

I would suggest the circuits should be fused as its possible that a fault will develop in your wiring from an unconsidered source (pinching or chafingfor example) and while Citroen no doubt tested their wiring thoroughly and hopefully eliminated such faults - you won't have that opportunity.

Don't forget the earth - an additional strap may help or a better wire to the existing bolt or something.

dan_the_v8man · Post by **dan_the_v8man** » 12 Dec 2006, 15:52

so where are people hiding these extra two relays, is there room around the lights thats suitable?