Switch logic

Hi,

I know I’ve asked this before but bear with me:

The interior light switch on my plus 2 doesn’t work. It’s a Off/On/On type that switches the panel lights on and also the interior lights.

The panel lights come on, but no interior lights. Now I have the dash out I thought I’d try and figure it out. I have continuity between the top and bottom connections on one side (for the panel lights) and the other (for the interior) when the switch is in the appropriate positions.

The wiring is correct (I think) - Power comes in on the Panel lights side and goes out to the bulbs, then I have the Purple/white wires on the interior lights side and an earth feed.

Question is, how do the interior lights get power? There is no continuity between any terminals going across from the panel lights to the interior lights circuits… Should their be?

Also, the interior lights only come on when the passenger door is opened, not the drivers door. I have checked the door switches and they seem to work fine… :confused:

This electrikery is doin me 'ead in

Ok, I’ll answer my own question:

The power comes from the fuse box.

Still can’t figure out why it doesn’t work though :cry:

Hi Rob

I have just had a look at the wiring diagram.

From the interior light the Purple wire is live and purple/white wire is earth.

The live comes via a connection from the brown/blue wire from the control box. So the interior light live connection should be live when the ignition is on and only the earth connection is switched.

The earth comes from the courtesy light switch or via the panel switch.
Looking at the diagram it looks like you should be able to switch the panel switch or the courtesy light switch and the interior light should come on.

If only one courtesy switch is working I would suspect the wire has come loose at the back of the switch that is not working.

That’s my opinion, hope it helps :slight_smile:

Jason

Thanks Jason,

Both interior lights work, but only when I open the passenger door. Panel switch seems to do nothing…

I’ve been checking continuity for all the wires and nothing seems amis. I can’t check for voltage at the moment and the dash is out and I don’t want to risk putting power through all those disconnected cables.

I’m sure the door switch is working ok but I’ll try swaping the connections to the warning light switch and see if that works (door warning lights work fine).

As it’s an earth switching system, where do I check for voltage?

Sorry, my brain goes numb when looking at wiring diagrams!

Hi Robbie

You need to check that there is an earth at the panel switch as the courtesy switch has its own earth.

Run a cable from the battery earth terminal and touch the purple/white wire connection on the panel switch, the light should come on.

Jason

Ok, thanks Jason,

I’ll give it a go