Side lights on all the time

The parking lamps are permanently grounded, so they are controlled ON and OFF by the power side of the circuit. Fuse 25 (10A) is for the left side parking lamps and Fuse 29 (10A) is for the right parking lamps. These fuses receive power when the tail lamp relay is engaged by the Electronic Timing Alarm Control Module (ETACM). It could be that the relay is not being commanded on, but the tail lamp relay is stuck in the ON position. It could also be that the relay is being commanded on, either appropriately or inappropriately. What I mean by that is the ETACM could be internally malfunctioning to where it "thinks" its receiving a request for the parking lights when its not, or alternatively, the ETACM is receiving a parking light request and is appropriately carrying out that task. In the case of the latter scenario, the headlight switch (incorporated into the multifunction switch) could be malfunctioning and inappropriately sending a parking light illumination request to the ETACM. To summarize, the two most likely culprits are a stuck tail lamp relay or a malfunctioning combination switch. You can read more about the symptoms of a bad or failing combination switch here: https://www.yourmechanic.com/article/symptoms-of-a-bad-or-failing-combination-switch-assembly

Power flows from the 12 volt battery through Fuse 19 (20A) and to the Tail Light Relay. This fuse and relay are housed in the under-hood fuse/relay box located at the left rear of the engine compartment. When the Tail Light Relay is commanded ON by the MICU, power flows out from the relay to Fuse 27 (10A) housed in the under-dash fuse/relay box located at the lower left end of the dashboard. From here, power flows to the side marker lights, license plate lights and tail lights. If a fuse is blown, check for water in the tail light assemblies. If a fuse isn't blown, it could be the the Tail Light Relay has failed or is not being commanded ON by the MICU. The MICU wouldn't send a command to turn ON without first seeing the request from the headlight/combination switch, so there could potentially be an issue there as well. You can read more here: https://www.yourmechanic.com/article/symptoms-of-a-bad-or-failing-combination-switch-assembly

Turn the parking lamps or headlamps on in order to illuminate the instrument panel and instrument panel cluster lamps. Voltage applies at all times through the TAIL fuse to the tail relay. Turning the turn signal/headlamp switch to the PARK or the HEAD position provides a ground path to the coil side of the relay to G202. The ground path energizes the coil of the relay. This closes the contacts in the relay. The closed contacts apply voltage to the IP dimmer illumination controller and all the illumination lamps. The illumination lamps are ground through the illumination controller. The controller is located on the left side of the instrument panel. Since the illumination controller is ground to G200, the lamps illuminate when voltage applies. The intensity of the instrument panel and the instrument panel cluster lamps is adjusted by the controller (4). The controller controls the intensity of the lamps by controlling the amount of current from the lamps to ground.Check the tail relay !

are you asking us to check your fuses.????? LOL.
why not check fuses. ANY time electrics of ANY kind fail.
this is first,, if battery is not dead.

"or side"
does that mean one side or both sides.?????
these are PARK lamp (old school name TAIL)
if the park fuse is blown (tail) then all parks go out.
some cars have park relay(s)
the FSM covers these facts and can vary by year and car type.

we have no Citroens here. so can not post schematics. sorry

I would hazard (!) a guess that the relay in the engine bay is toast, the headlights are on a different circuit and a different relay. Check the fuse box if you already haven't, if all the fuses look good then verify that the wiring from the fuse panel to the tail lights is getting power. There is also another relay at the back on the driver's side for the tail lights if I remember correctly but as you have brake lights I suspect that there is more than one problem here.

Your Tail Lamp/Park Lamp system is pretty easy to check. ayou can check to see which part of the system is failing by checking for power and ground at the socket for the tail lamp relay. The tail lamp relay is located in the driver's side junction box under the left side of the dash. It is the relay that is second from the bottom at the far left.
To check the circuits, you just need a 12 volt test light. Remove the relay and do the following tests:
Connect one end of the test lamp to the battery NEGATIVE post. with the other end probe pins 1 and 5 of the relay connector. Both of these pins should have power (light your test light) at all times. If they do not, or if one is hot and the other one is not, the problem is most likely in the junction block itself.

Switch your test lamp lead from the battery negative terminal to the battery POSITIVE terminal.
Probe pin 3. Your test lamp should light, but may be a little dim. This is the circuit through your tail and park lamps to ground. Your park lamps should also light dimly when you do this. If the light does not light at all, then you need to check for a blown fuse at the 10 Amp "TAIL" fuse located inside the drivers side kick panel fuse block. If this fuse is blown, you will need to trace your tail and park lamp circuits to find out where they are shorting.

With your test lamp still connected to battery positive, probe pin 2 at the relay connector. This connector should not do anything until the headlamp (combination) switch is turned on. When it is turned on, your test lamp should light. I am not absolutely certain, but you MAY have to turn the ignition switch on to get this to work. This circuit is actually grounded by the body control computer, and the service manual does not say if it will work without the ignition on. If your test lamp does not light with the light switch turned on and the ignition switch on, then the problem is either the light switch, the body computer, or the wiring in between them. You will need a scan tool that can read live data from the body computer to find out if the body computer is receiving the signal from the headlamp switch. If you have not located the cause of the problem at this point, I would recommend getting with somebody that has the proper equipment to diagnose your computer system.

Good luck,

Dave

It's probably not the fuse if it's only one side. The fuse will power both tail lights. I would check the bulb first.

Good Luck!

hi ,ive got exactly the same problem on my cherokee,ther is a sound of a relay buzzzing under the dash.when i turn on the side lights,nothing,turn on headlamps and i get dip plus side lamps,no dash lights though,after a whils all lights fail but i can pull/flash main beam and hold it on,im taking out the dash area tomorrow,friday ,i have aspare headlamp switch and relay/fuse box ,my mobile is 07712128561,ill keep you posted

I had the same issues. Dash dead, tail lights dead. Fuses were fine, Dimmer relay was fine...So I got to the Tail Light Relay.

Removed the glove box, one screw on the right. Reach up (above the space where the glove box 'area' would be and there are 3 or 4 relays all sitting on top of a junction box. All of them were loose. I pushed them in...and voila! I was getting scared after the obvious.

Both the dash lights and headlamps, including the tail lights are fed through a fuse link under the bonnet, then the tail, dash lights are run through fuses as are the headlamps. Firstly, check the fuses electrically not visually. Use a test probe (available from your local auto parts shop, not expensive) and clip one end to a good ground on the vehicle chassis and use the pointy end to check both ends of each fuse, the test lamp should light up on BOTH ends. If it lights up on one end only, then that fuse has failed and should be replaced. If it does not light up at either end of the fuse, that circuit is without power so turn on the ignition and lights but DO NOT start the motor. Then check the fuses again. If all looks good, locate the light relays which could be under the hood in their own enclosure or plugged in under the dash and check each one for inputs and outputs. If the relay pins are numbered, you should have power to pins 85 OR 86 but not both and 30. Pins 85 and 86 are the coil connections and a power supply and ground connection to these pins should turn the relay on (you should hear a click) pin 30 is the main load supply and pin 87 is the output supply. This means that pin 87 should be active whenever the relay is turned on. power missing from pin 30, check fuses and fuse links. Power at pin 30 but not at pin 87 when the relay is on, replace the relay. Essentially, the light switch turns on the relay and the relay switches the power to the lights, one relay for dash and tail and two relays for the headlamps (high and low beam). You may find that the vehicle has two headlamp relays for each side headlamps, a high and low beam for the right side lights and the same for the left. If you have no power to one of the switching connections (85 and 86) then again check fuses and check the light switch itself.