Citroen XM Forum

Yeah think it’s called a ballast, one each side for extra voltage to the bulb because it’s so terribly dim. If it’s as you say, if I put another stalk in would it do the same and why? 2 years and it seemed fine.

Hi yes ballasts think they re called, one each side to add extra voltage to the dim factory dips. Could this have cause the damage after 2 years? How do I get the stalk off and is it likely to do it again?

If it is the ballasts have caused the issue then what has probably happened is the lights switch has been overloaded when the ballast first comes on, so the switch is now welded closed.
To remove the stalk you remove upper and lower steering column shrouds, by the screws through the lower shroud, then the stalk screws should be accessible.
If you can't access the screws you may need to remove the steering wheel.

The dipped beam won't work without the relay fitted. Is it in place behind the left headlamp?

You need to investigate using a test lamp/DMM and the circuit diagrams.

Thanks diesel man. I’ve had a thought, I badly connected a new horn and the shroud area smoked, I wonder if it was that rather than the light ballasts which were done properly by someone else. It could have finally given way. So if I replace the stalk hopefully I won’t have further problems. Would you concur?

Possible.
Smoke = heat, so the switch unit could have melted shorting out all the contacts.
Disconnect the switch plug to see if the lights go out.

Where is that?

Where you would expect, under the steering column.

Oh right yeah ok my next job is to strip.

Hi again all. I have replaced the stalks on the steering wheel and still the side lights stay on all the time unless I remove the battery terminal. I’m convinced that it has something to do with the ballasts I introduced and I’ve blown something. Unless it’s an individual wire from the interface by the steering wheel onto the stalk apparatus it must be something to do with the wiring at the front where the headlights are wired in. I’ve also changed the relays up there but still no joy. As far as wiring from the stalk, all the other lights and indicators work except the dipped beam. I wondered if it was the dipped bulbs gone but would that blow what it blew and would the sidelights remain on if that were the case. Anymore ideas? Btw where do the wires on the stalk apparatus interface, go to, is it the ecu?

newxmman wrote: ↑

Sun Nov 06, 2022 4:56 pm

Hi again all. I have replaced the stalks on the steering wheel and still the side lights stay on all the time unless I remove the battery terminal. I’m convinced that it has something to do with the ballasts I introduced and I’ve blown something. Unless it’s an individual wire from the interface by the steering wheel onto the stalk apparatus it must be something to do with the wiring at the front where the headlights are wired in. I’ve also changed the relays up there but still no joy. As far as wiring from the stalk, all the other lights and indicators work except the dipped beam. I wondered if it was the dipped bulbs gone but would that blow what it blew and would the sidelights remain on if that were the case. Anymore ideas? Btw where do the wires on the stalk apparatus interface, go to, is it the ecu?

By ECu, do you mean the bulb failure warning circuit, if so, the answer is yes it does.

The feed to the sidelights also feeds the number plate lamps, but that splices out of the loom before the bulb warning unit.
The bulb failure unit is mounted under the right side dashboard.

Check to see if the numberplate lights are permenantly illuminated as well as the sidelights, then pull F10 and check both again, they should be out. Re-install F10.
Next disconnect the bulb failure module and see if the sidelights are out. If they are still lit the fault is in the wiring to the sidelights themselves, not the switch, column stalk, or bulb failure module.

The dip beam headlamps only have power with Ign on, whereas main beam are fed via direct battery power via the column stalk.

The dipped beams power comes from one of the relays behind the L/h headlamp, the leads are Yellow for +12v feed and headlamp +12v feed, Brown for relay coil Gnd and should be green for trigger from the lights switch.

Check for +12v at the bulb using a seperate, known good, test lamp. If the bulb illuminates your headlamp bulbs are blown.

Perform a continuity test between the headlamp dip beam bulb and the relay socket to ensure you have the correct relay and pin.
If there is no +12v pull the relay out and bridge the heavy duty contacts, (yellow wires) with a test lamp. This should bring the lamps on, possibly at low brightness depending on the test lamp wattage, and tests the feed and all high power wiring.
If the test light shines brightly but the headlamps still don't illuminate then there is a short to Gnd in the headlamp wiring.


Use a lest lamp or Dmm to probe the trigger wire to see if there is +12v from the stalk switch.

Pin 1 = +12v trigger
pin2 = Gnd
pin 3 = +12v feed to dip headlamps
pin 4 = N/c
Pin 5 = +12v feed from battery.


Have you downloaded the electrical schematics from page 1 of this topic?
Do you have a Haynes manual?
Both have accurate wiring diagrams for the lighting on your Xm.

Check the above items and come back if you need further assistance.