Interior light - Driver side not working

Need technical Q/A then you're in the right place

Moderator: martauto

Post Reply
User avatar
E30M3EVO
E30 Zone Newbie
E30 Zone Newbie
Posts: 103
Joined: Mon Sep 14, 2009 11:00 pm

Tue Sep 20, 2016 9:25 am

Guys,

When i open the door the interior lights do not come on. But when I open the passenger door the interior lights come on.

Troubleshooting steps so far taken:

1. Checked driver side bulb - ok
2. Swapped the dome for a known working
3. Swapped the door switch

Been told it may be a wire in the A pillar that may be at fault or central locking system.

Can anyone shed some light on this or experienced a similar issue.

Thanks
User avatar
ChrisHC
E30Zone Contributor
Posts: 515
Joined: Fri Oct 23, 2015 11:00 pm

Wed Sep 21, 2016 2:06 am

It is not clear from your post whether the driver's side light comes on when you open the passenger door. If it does, then there is nothing wrong with the light. If it does not, then there might be something wrong with the light. The three way switch on the light is a rather crude device and is subject to the heat from the festoon bulb; it might be the problem. I would start by testing whether there is power there when the driver's door is opened and whether there is a good earth there and the switch works properly. I do not see how the central locking can be involved but the interior light delay unit is mounted alongside the central locking unit to the side of the driver's footwell.
User avatar
Brianmoooore
E30 Zone Team Member
E30 Zone Team Member
Posts: 49353
Joined: Mon Jan 10, 2005 11:00 pm

Wed Sep 21, 2016 9:32 am

The first thing that needs to be established is whether you have the fairly rare option of an interior light switch off delay 'relay' fitted to your car. These are connected to the driver's door only, so if fitted, and faulty, will only affect that door.
Unscrew the driver's door pin switch again, and tell us what colour wires are attached to it.
User avatar
E30M3EVO
E30 Zone Newbie
E30 Zone Newbie
Posts: 103
Joined: Mon Sep 14, 2009 11:00 pm

Wed Sep 21, 2016 9:33 am

Thanks Chris,

I was checking this lastnight, the following are the findings:

1. When I open the passenger door, both passenger and driver side dome light up
2. When I open the driver side door, none of the dome's light up.
3. Manually switching on the driver side dome works

I have checked the switches and swapped them are working.

So i assume it may be the wiring..? Where is the earthing..?

Thanks
bobbin1982
E30 Zone Squatter
E30 Zone Squatter
Posts: 1508
Joined: Mon Mar 23, 2009 11:00 pm
Location: Norwich,Norfolk

Wed Sep 21, 2016 6:00 pm

Brianmoooore wrote:The first thing that needs to be established is whether you have the fairly rare option of an interior light switch off delay 'relay' fitted to your car. These are connected to the driver's door only, so if fitted, and faulty, will only affect that door.
Unscrew the driver's door pin switch again, and tell us what colour wires are attached to it.
Driving my digger!!!!
User avatar
E30M3EVO
E30 Zone Newbie
E30 Zone Newbie
Posts: 103
Joined: Mon Sep 14, 2009 11:00 pm

Thu Sep 22, 2016 10:03 am

Thanks will have a look today and let you guys know. :)
User avatar
E30M3EVO
E30 Zone Newbie
E30 Zone Newbie
Posts: 103
Joined: Mon Sep 14, 2009 11:00 pm

Thu Sep 22, 2016 6:17 pm

I have had a look, two wires are connected to the switch of the following colour:

Brown/Yellow
Brown/Blue (purpley blue)

Thanks
User avatar
Brianmoooore
E30 Zone Team Member
E30 Zone Team Member
Posts: 49353
Joined: Mon Jan 10, 2005 11:00 pm

Thu Sep 22, 2016 7:26 pm

Brown/blue is the wire for the relay that enables the windows to work with the doors open and ignition off, and brown/yellow is indeed the wire that controls an interior light delay unit, so it looks like you have one fitted.
If there wasn't, the second wire would be brown/purple.
The light delay unit uses the same power feed (red/black wire) as the central locking, so the first question is: does the locking work correctly?
There is a switch connected to the driver's external door handle that needs to be in working order, along with the wire from it to the delay unit, which passes through the infamous A pillar plug and socket for the door wiring loom. This is a brown/green wire.
Wiring diagram here: http://www.autolib.diakom.ru/CAR/BMW/19 ... /fig11.pdf
User avatar
E30M3EVO
E30 Zone Newbie
E30 Zone Newbie
Posts: 103
Joined: Mon Sep 14, 2009 11:00 pm

Thu Sep 22, 2016 10:08 pm

Thanks Brian

The central locking works perfectly and works with the alarm fob aswell.

I will check the brown/green wire and see if its all connected accordingly.

:D
Post Reply