LCR courtesy light won't go out after locking

[mph]

I found my battery was draining after a few days and also the courtesy light was flickering on and off at random times during driving. I wondered if this was the problem and when I took the light unit out found the plastic pins on the connector socket had melted slightly, probably due to overheating.

I managed to find a replacement light unit and fitted. Now the light stays on when it should fade off after locking the car. Where would I look to diagnose this?

 

[mty12345]

I found my battery was draining after a few days and also the courtesy light was flickering on and off at random times during driving. I wondered if this was the problem and when I took the light unit out found the plastic pins on the connector socket had melted slightly, probably due to overheating.

I managed to find a replacement light unit and fitted. Now the light stays on when it should fade off after locking the car. Where would I look to diagnose this?

I take it you have the switch in the right position? I'm sure you've checked but thought i'd better ask that first lol. If so then I can only think the switch is faulty on your new unit. Try cleaning it like this...

 

[mph]

Yes the switch is in the correct position. In fact either position results in the light remaining on. The contacts are clean. I can't see it being a faulty switch if the light stays on when it should go off?

 

[mty12345]

Yes the switch is in the correct position. In fact either position results in the light remaining on. The contacts are clean. I can't see it being a faulty switch if the light stays on when it should go off?

When it's in the 'Auto' Position, the operation is controlled by the central convience unit. If that switch is sticking, shorted by corrosion, or the contacts are bent so that it's not going into that Auto postion (even though the plastic part looks like it is) , then it would mean that it's permanently getting power when it shouldn't be.

Either that or you have plugged it in back to front. There is a keyway designed to prevent you doing that, but probably still possible.

There are only 3 wires going into it, ground, 12v and the 'switched live' from the CC unit.

Edit: The only other option would be that it thinks a door is open, but if that was the case it should set the alarm off, so i can't really see that being why, especially if it was ok until you swapped the light

 

[mph]

My car has been in a local garage for 2 months and they have failed to find the battery drain issue. I replaced the courtesy light with a new one so it's not that. Then they thought it was the ignition switch, so replaced that, but still have the drain. Now they have given me the car back after giving up.

Whilst the car is off, I measured the current through each terminal shown on the attached pic. The one that's disconnected has a 2A drain!
Does anyone know what that cable supplies?

 

[Alexis27]

Interior relay panel
Water can sometimes trickle into the panel under the steering wheel, so I'd pull the relays and check for rusty contacts.