Indicator Issue on C3 Picasso (2014)

[CitroJim]

I'm sorry, life and my poor memory conspired here...

I may have a bit of time today and will look...

What are the results of your tests and investigations so far?

[GiveMeABreak]

Check your rear indicator connection at the connector which is PIN 3 for the indicator on both sides and the earth in pin 4. Note there are separate earthing points for the rear indicators, so the earth is usually the issue. Check that the pin is ok and that the pin sockets show no signs of burning or melting.

We had a bad earth on our C3 at the pin on the rear left and I had to put a bypass in as the socket melted, being that Citroen don't provide a thick enough earth cable to handle the load causing the melting.

The specific earthing point location for the rear right indicator is MC70 shown in the diagram:

[the_wondering_owl]

I'm sorry, life and my poor memory conspired here...

I may have a bit of time today and will look...

What are the results of your tests and investigations so far?

hi there, again like you i have not had much time to do further fault finding as been away on holiday for a week and only got back late last night, hope to have time to take a better look today or tomorrow

[the_wondering_owl]

Check your rear indicator connection at the connector which is PIN 3 for the indicator on both sides and the earth in pin 4. Note there are separate earthing points for the rear indicators, so the earth is usually the issue. Check that the pin is ok and that the pin sockets show no signs of burning or melting.

We had a bad earth on our C3 at the pin on the rear left and I had to put a bypass in as the socket melted, being that Citroen don't provide a thick enough earth cable to handle the load causing the melting.

The specific earthing point location for the rear right indicator is MC70 shown in the diagram:

Hi Mark, thanks for the explanation and diagram, hope to take a look today / tomorrow with the multimeter, on my initial investigation it does not looks melted, i may try putting the light cluster on the other side and seeing if that works elimination the cluster being the issue

[the_wondering_owl]

Check your rear indicator connection at the connector which is PIN 3 for the indicator on both sides and the earth in pin 4. Note there are separate earthing points for the rear indicators, so the earth is usually the issue. Check that the pin is ok and that the pin sockets show no signs of burning or melting.

We had a bad earth on our C3 at the pin on the rear left and I had to put a bypass in as the socket melted, being that Citroen don't provide a thick enough earth cable to handle the load causing the melting.

The specific earthing point location for the rear right indicator is MC70 shown in the diagram:

Hi Mark, thanks for the explanation and diagram, hope to take a look today / tomorrow with the multimeter, on my initial investigation it does not looks melted, i may try putting the light cluster on the other side and seeing if that works elimination the cluster being the issue

Hi Mark,

just wanted to clarify a couple of things you mentioned here.

PIN 3 : you mean the connector coming our of the wiring loom right which is. How to I identify which one PIN 3 is, i.e. which side is PIN 1 (i will post a picture of the connector tomorrow)

When you say "Check your rear indicator connection at the connector which is PIN 3 for the indicator on both sides and the earth in pin 4"

do you mean here that PIN 3 for left indicator and pin 3 on the right indicator? what should i be checking here, that i have 0 resistance between pin 3 and earth (PIN 4) and then check for pin3 and the chassis earth is pin 3 to pin 3 is 0 resistance.

Also where about is MC70 This is presumable the actual earthing location for the right hand light cluster, its not 100% clear as to its location, it looks like its in the headlining from the diagram but that maybe me missreading the diagram

Apols for too many questions here (first time trying to fault-find car electrics here)

[the_wondering_owl]

Mark, in fact rereading that i think by both sides of PIN 3 you mean at the end of the connector and also before the connector if so to test before the connector do i need to cut the wire for PIN3 to do the impedance test to earth here?

[GiveMeABreak]

I am talking about the physical connector to the lighting cluster at the rear right (which is the one you said is faulty). The pin numbers are on the plastic socket as you can see from the one I did on ours that shows a damaged earth which on ours was Pin 1:

The pin numbers are shown clearly at the top.

Click Image to Zoom

[the_wondering_owl]

Marc,

Fantastic that helps and thanks for the helpful photo too, i did check the connector earlier and definatly no sign of damage like the one you showed but stick a multimeter between PIN 3 & 4 and im guessing i should have no resistance here which gives then indication of no earth problem, if i do have an open circuit here i should trace the earth connector back to the MC70 earth point. do those cable just pull out from the connector (dont want to tug on them too much?

dont support you can remember where exactly that earth point is as the wiring harnes here goes into the top of the boot and im guessing into somewhere under the roof lining or perhaps the rear window plastic covering?

thanks again for your assistance

[GiveMeABreak]

The wiring just goes back from the top right lighting cluster and routes back down along the sill and back to the engine compartment looking at the diagram. Not much help though. I would initially focus on the connections at the rear cluster and check those - but the earth on each side of each rear lighting cluster is a common earth (one for the right cluster and one for the left cluster) for the other lights (which is why on our C3 it was overheating causing intermittent issues with bulb out warnings).

[the_wondering_owl]

great many thanks give me some direction to look at tomorrow when its daylight as you say its probably an issue around the connector and i guess i can take a wire from the connector and splice run it into the light cluster itself as if it was an earth connection and the earth is a common earth betwen both connectors then they would both be playing up

[GiveMeABreak]

Yes, I had to take a separate earth, but you should be able to test whether it is an earth or not by using a separate earth to the bodywork and the earth pin then test the indicator.

[the_wondering_owl]

thanks i will give that a go tomorrow, thanks for all the advice will report back

[the_wondering_owl]

So i think i have found the issue here, connected a wire to the earth on the bulb to the car chassis fixed the problem with the indicator not flashing.

i then tested the resistance on the connector coming the car (earth pin here to the ground on the car) and it was open circuit, im guessing now that a connection before the connector from the wiring loom directly to the light cluster should resolve the issue (as the earth should be connected to the car chassis as its a common earth with the other indicator)

one thing to note is the connector coming out of the car only has 4 wires (i think yours had 6 showing in the diagram) see the attachment for reference (it also has no numbering on it unlike the one shown in your photo)

[the_wondering_owl]

a little update, i spliced the earth from before the main connector (in the wiring loom) into the earth cable after the connector going to the indicator light. the indicator still does not light up, however running a lead from the newly splied cable at the point past the connector to the light bulb earth point does kick in the flashing.

my consution is that both the wiring loom connector and the connector on the indicator housing have both been damaged (prob a current surge in a thing wire?)

the bulb house looks like the cables going in have been sealed in and not serviceable, so i think i will need to order a new bulb housing and rewire

https://eurofrance24.com/catalog/produc ... sso-13257/

on the yellow indicator holder here you can see what looks like melted plastic (which i think is some kind of weather proofing) , which i dont think can be removed to re-wire

looks like i can not buy just the orange holder though

thats my working assumption now