Interior light wont turn off - PLEASE chuck in your 2c worth

[brw1994]

Ok this has me stumped ever since the other night I have not been able to make my interior light turn off when I close all the doors. When all doors are closed the light dims and flickers.

So far I have checked the following:
Removed and checked all fuses
Removed and checked all pressure switches on the doors
Made sure my battery terminals etc were all on tight
Turned the car on to see if it made any difference
Tried in all key positions
Checked both lights
Turned the dash light dimmer down

I am f'd if I know but it's doing my head in.. Things I have done lately have included fitting a pulsar alternator messed a little with dual battery system. I have removed the dual battery to see if it affected it and no. I have also removed the alternator plug and no avail.

The only thing that I can think of that may have had some effect it that I plugged a phone charger into the cig socket and heard a little zap I guess you'd say and the little green light around the lighter died. (Would also appreciate info to fix this)

I personally think something is shorting out or a relay is f'd but don't know where the relay for the int. lights is located...

Please feel free to mention anything I wont get offended because I am trumped on this..

[Col.T]

G'day mate,
not being a sparky of any description, I can't help, sorry. To help others help you though, it may pay to let them know what wheels you're driving as I'm guessing the circuitry will vary between models.
Would have bet the house on it being in one of the door switches though.
Have you downloaded the complete manual for your model? Follow the circuit in the electrical section because that will show everything which may be on the same 'line'.
'Cause I'm old and lazy and not quite with it, I'm not going to do that yet but I'd be a bit surprised to find the cigarette lighter is on the door circuit. Let's know what model and if it's a GU 3.0CRD I may be able to look it up for you.
Help is probably on the way though.
Good luck
Col

[Ben-e-boy]

Have you done any wiring recently?


Disconnect the battery and do do a continuity check either side of the interior light switch in all positions. That would my first check.
If that checks out it might be getting a back feed from some where. You need the wiring diagram now, full the fuse for the interior light and check for power, if there is the pull the other fuses individually checking for power and then try and find the back feed. Try that first and let us know how you go,

[brw1994]

G'day mate,
not being a sparky of any description, I can't help, sorry. To help others help you though, it may pay to let them know what wheels you're driving as I'm guessing the circuitry will vary between models.
Would have bet the house on it being in one of the door switches though.
Have you downloaded the complete manual for your model? Follow the circuit in the electrical section because that will show everything which may be on the same 'line'.
'Cause I'm old and lazy and not quite with it, I'm not going to do that yet but I'd be a bit surprised to find the cigarette lighter is on the door circuit. Let's know what model and if it's a GU 3.0CRD I may be able to look it up for you.
Help is probably on the way though.
Good luck
Col

Yeh that's exactly what I was thinking about the cig lighter. It's a 1988 Ford Mav

Have you done any wiring recently?


Disconnect the battery and do do a continuity check either side of the interior light switch in all positions. That would my first check.
If that checks out it might be getting a back feed from some where. You need the wiring diagram now, full the fuse for the interior light and check for power, if there is the pull the other fuses individually checking for power and then try and find the back feed. Try that first and let us know how you go,

Haven't done any wiring lately other than changing Spot lights. How do I do a continuity check? I have heard of them before never done one though and I like the idea of pulling the fuses but I remember the light going off when I pulled its fuse out

[Ben-e-boy]

Do you have a multimeter? You need one to do a test.

[brw1994]

Yes I have a multimeter

[mudnut]

I am looking at the diagram for a GQ as I type this. The circuit is pretty straight forward. There is no relay, just two lights with switches and the four door switches that connect to earth.

[daggy]

Try removing the bulbs and putting them back in. They could possibly be earthing to the roof. I had the problem in my GU.

[Ben-e-boy]

Haven't done any wiring lately other than changing Spot lights. How do I do a continuity check? I have heard of them before never done one though and I like the idea of pulling the fuses but I remember the light going off when I pulled its fuse out

a continuity check will tell you if if the switch contacts are a high resistance joint or shorted. Put one of the leads from the meter on either side of the switch contact you shoud have continuity when on and nothing when off.

[happygu]

Check for Voltage at the light itself 0Volts is Off, and 12V is ON.

You may have a broken door switch, and I would check both the rear doors first ( especially the big rear door ), and then open and close each of the door switches one at a time. You can pull the wires off the switches, and check the resistance of the switch itself, as with the switch pushed in ( simulating Door Closed ), it should be Infinity Ohms ( Large Number ), and with the switch out, you should have 0 Ohms as the switch should then make a circuit.

Mic