Interior light issue (Doesn't go off)

[Enlightx]

can any one help with working out why if i have my courtesy light in the central position the lights NEVER goes off... even when the car is double locked and 10 mins later

if i close the door doesnt go off, all door sensors seem okay as if i open a door i get the door open message on the dash for each door and the boot.

i have messed around and once it started working. off then open the door and on then off i powered on and off car and wasn't working again.

Car is a focus 2010 MK2.5 

any ideas or tests i can do would be a great help. stupidly iv known about this for 6 months and only remembered now its got dark.

[Tasape]

Not that im an expert but a couple of things come to mind

firstly  check the Switch if possible and clean the contacts as it could just be a bit of dirt stopping it or a poor connection

secondly   try changing the bulb  it may have malfunctioned  

[F0CUE]

Defo the switch ever since I pulled mines off wrong the plastic came away instead of the full unit and messed with the switch and mines won't go off only when switch on off position have fiddled with the copper type prongs but cant get right ford make things weird lol

[Enlightx]

well just had a thought that i can change the back for the front and try it that way. did the same though so i got a multi meter and tested the plugs 12V on each plug meaning its not the switches. check both switches and they both test okay.

give up and reassemble all and now its working. but it has done this before when i asked the previous owner he said yeah sometimes it gets confused and you have to mess about closing and opening the door to correct it.

has anyone else heard of this??

[ashmicro]

I made a bit of a pig's ear of changing the bulb in my car's interior lamp, and it wouldn't go off. I must have taken the lamp unit apart about 8 times and put it back together before it would behave. Not a well designed thing.

[Enlightx]

so drove it home last night 5 mins into driving, both courtesy lights came back on while i was driving.

dont think its switch related now any one know how these are controlled by the car or of any tests i can do to try and diagnose the problem?

[F0CUE]

Do the Footwell lights come on too?

[Enlightx]

dont think i have footwell lights if i do they dont come on :) but dont think i have them 

its a 2010 focus zetec s Mk2.5 stop start

 

from what i understand looking at it the courtesy lights are not run by the gem unit as the switchs are hard mechnical lights. you have 1 ground and 2 12 V then the switch seems to go 12v to gound , 12v(controlled by something) to ground, ground to ground.

im thinking its some sort of computer controlled thing or a sensor somewere but all the door sensors and boot sensors seem okay as if i open them i get door open on the dash.

[Enlightx]

something to add. if i have the lights in central position. even if i get out of the car. double lock wait 10 mins lights are still on

 

 

[F0CUE]

You do have them they just didn't come with bulbs if you look under there to the far left drivers side and far right passenger side you will see the connectors for w5w wedge bulbs if u have a spare plug it in and see if that stays on too then it may be door switch related 

[Micro]

25 minutes ago, F0CUE said:

You do have them they just didn't come with bulbs if you look under there to the far left drivers side and far right passenger side you will see the connectors for w5w wedge bulbs if u have a spare plug it in and see if that stays on too then it may be door switch related 

I don't have them in my car. I have the hole, but no harness. The light on the middle setting is controlled by the GEM, and will gradually dim the lights til they're off.

The lights will dim and go off if you turn the ignition to II with all doors shut - does it do this? If you can test both 12V supplies whilst you do this it may help.

You can also see if there is a door sensor fault, turn your ignition off and take your keys out. Pull the main beam stick so your lights come on, get out of the car, shut the door, and lock/double lock it. The headlights should go off after 30 seconds. If they stay on to 180 seconds there is a door sensor problem somewhere.

[Enlightx]

Hi Guys

Just been doing some more work on this. got me an ELM327 and modded it so i can look at the GEM module to see status of things. looks like my door sensors are okay but the main thing i found is theres a control for courtesy light... which is off yet the lights are on. i open door and control changes to on. so its not a computer or sensor issue the car is doing what it thinks is correct in terms of the gem unit.

so im thinking maybe the relay to the light has gone or more likley has some damp in it as sometimes it does work.

anyone know were the relay for the courtesy light is? im really hoping its not built in the gem unit as this would mean replacing the whole unit. (any one heard of people repairing gem units?)

 

thanks to everyone for the help so far

also had a look iv got no footwell bulb holders :( next thing to sort after this courtesy light is solved.

 

[mjt]

It's not controlled by a relay because it normally dims out rather than abruptly switching off. This means it'll be controlled by a semiconductor, probably pulse-width modulated, in the GEM. As you've already discovered all the interior lights are supplied with a constant 12V and are switched on by grounding the other side of the bulbs. For the map lights this is done directly by their switches but the courtesy light goes back to the GEM via the auto position of its switch. A short to ground anywhere along this path would keep the light on.

The fact it started working for a while after you'd been messing with the light units suggests an intermittent short somewhere around one of the light units is the most likely cause. Note that the GEM path goes in parallel to both front and rear units so the short could be around either.

[Enlightx]

yes forget it dims.

in the unit it self i get 3 wires to the unit. currently im getting 12V , 12V ground.

i was thinking that 12v was the for the always on position, the other 12 V was for the variable position (middle), and ground for ground.

are you saying i should have 1 12V and 2 grounds? 

[mjt]

I was going by the diagram in the Haynes manual so maybe one has to treat that with a bit of circumspection. It shows one ground, which goes to all three switches, and two feeds from the GEM. One of these appears to come from the battery saver relay which is what powers all the ancillaries up and times out some time after the ignition is switched off. This will be a constant 12V and goes to all three bulbs. The other GEM feed goes to the 'Auto' position of the courtesy light switch. This will be ground when the GEM switches the bulb on but when it switches it off it will either be open-circuit, in which case you'll read 12V via the bulb, or it might go to 12V if there's a pull-up in the GEM. I hope that makes sense.

[Enlightx]

thanks mjt great help gives me something to work on. need to get me a haynes not thought about it for this car yet as not had an issue lol

[Micro]

Just to be sure we're not overlooking things, are you sure your switch in the light is correctly switching? Iirc mine has lots of metal strips and the switch is finickity at the best of times.

[Enlightx]

seems okay it also happens on both rear and front courtesy lights. iv also tried swopping them around with the same effect.and also having only 1 plugged in with the same effect.

still waiting for my haynes guide to arrive.

can someone tell me were i will find the gem unit ?

[mjt]

In the passenger footwell behind the glovebox. It's part of the passenger fuseboard.