Headlamp relay mod.

[IrfanIbrahim]

Browse through many threads, still does'nt understand a bit.
Can someone who did the relay mod explain in detailed on how to do this mod. If possible can please list the item needed. Pictures would be a better help.

[Monkeyfeet]

It's not too difficult to do if you can or know someone that can solder/ attach crimps and do a bit of basic wiring. it sounds worse than it is, really!
However if you're not electrically-minded and don't know anybody that is, there's usually plenty of guidance here, you just have to wait for the right people to wander along..
Basic principle is simply getting a relay to handle the headlight current instead of the headlight switches alone.
This in practice means connecting the existing headlight wires to switch the relay/s on/off. You'll need to run a (fused) supply to the relays from the battery positive and to provide the relay/s with an earth (negative) connection.
Not too sure how to explain details next - post if this makes sense so far (or apologies if I'm teaching how to suck eggs!)

[IrfanIbrahim]

I'm definitely not an electrically-minded guy. Haha. If someone can provide enough information about relay spec, wiring spec, i'll try to find someone who knows how to do it.

[Sean602]

I'm definitely not an electrically-minded guy. Haha. If someone can provide enough information about relay spec, wiring spec, i'll try to find someone who knows how to do it.

Not got a clue as to the mod needed on the xantia? but un fused and full power going through plasticky switches- a habit Citroen got in to looong time ago! Common mod on 2cv is to use these relays

keeps it all neat and tidy

[jgra1]

I will do a diagram

[jgra1]

did one, who can i email it to? I cant post it here, at work...

it may not be spot on..

C5 and Xant both benefit from this mod...

[Xaccers]

did one, who can i email it to? I cant post it here, at work...

it may not be spot on..

C5 and Xant both benefit from this mod...

PM inbound

[Xaccers]

Jgra's diagram can be found here.

It covers the wiring layout of both a high and a low beam relay.

[DickieG]

Here's an excellent link which fully explains the benefits of carrying out the modification including measuring the present light output complete with full wiring diagrams including the relay connections.

To be honest having carried out this modification to several Xantia's I wouldn't bother with doing the main beam's, I also took the new feed directly onto the headlight bulb because the gauge of the original wiring is very low plus this eliminates another block connector which is another potential source of voltage loss. To do this you'll have to drill a small hole onto either the rear headlight cover or on the underside of the headlight but this entails removing the headlight to gain access (not difficult), whichever way you choose make sure the hole is no larger than the wire to avoid dampness within the headlight.

For the main feed to the relay I take it directly from the battery then fuse it prior to the relay's (one each side) with the earth coming from one the main earthing bolts on the inner wings, the whole job isn't difficult but don't underestimate the amount of wire you'll get through as it'll be quite a lot.

[Xantidote]

I wouldn't bother with doing the main beam

I agree- suggest you do the dip, and see the improvement, before considering the main beam - only done the dip on my S1

[IrfanIbrahim]

Thanks for the diagram and info! Sorry for a late reply been outstation past few days.

[andy5]

I wonder how much the bulb life improves by not having that extra volt or three quarters at the holder, and how the results of doing this mod would compare with having uprated bulbs instead and not doing the job

I say this partly because I've just bought some Osram Silverstars cheaply, and it strikes me they might last longer if I don't actually do this mod.

[IrfanIbrahim]

Does changing the normal bulb with an uprated bulb without relay mod helps alot? Which give better improvement, the relay mod with normal bulb or uprated bulb without the mod?

[jgra1]

not scientific but I would say that a decent bulb will give imrpovement, and the relay mod would also.. and both would give more

re headlamp bulb life.. I never seem to get through them / relay or not.. it seems very rare that I ever have them go..
saying that, I never buy the things from a shop.. they just appear from old headlamps lying about.. I would be more concerned if I was paying a tenner a time for one..

[IrfanIbrahim]

Any improvement so I could see roads better at night should helps. Haha. Guess I should try with an uprated bulb first and see the difference. And relay modded it if that was'nt enough.