Faulty interior light circuit NC

Technical Area Electrics & ICE
1

Recently my interior light on my NC hardtop has stopped working. With a multimeter I have confirmed that the Room and illumination fuses are fine and the bulb is fine too. The door open switches are fine too as the dash light comes on if either door is opened. Does anyone have a wiring diagram they could share, or any tips on possible solution? Thanks!

2

Mellens for manuals, based on LHD though doubt that has any impact.

https://www.mellens.net/mazda/

3

Thanks Ian

4

Does it not work off both doors?

Have you seen this topic?

5

Neither door works, or even manual on.

6

I have this too on my car, it used to be fine and I could operate the interior light independently, but now it only works when a door is opened.

I just live with it and click the door of the latch if I need the light on.

There’s a thread about this in the flyin miata forum and the consensus is that replacing the interior light fitting fixes it.

7

Thanks, nothing works with mine. Will have a look at the light fitting tomorrow to see if anything is loose.

8

I no longer have an NC as I traded it for a 2019 RF auto but I was never able to rectify the ignition illumination. The bulb was fine so in the end I ignored the problem especially as someone reckoned you had to change the fascia display!

9

I had this problem on my NC where opening the passenger door would activate the interior light but the driver’s door wouldn’t.
I solved it by running another earth wire from the overhead light to the door switch on the driver’s side.

10

Problem resolved. Just a loose connection at the light socket! Thanks everyone for your help!

1 Like
11

Ordinarily most interior light circuits on slightly older cars that I’ve come across just involve buttons in the door shuts that push to break. When the door is open a spring forces the button out and the end contact on the wire can then make with the body to pick up a negative and make the circuit. If you ever get an issue where one door doesn’t trigger the light it’s worth taking the switch out on that side and if it’s a single wire then earth it to chassis bare metal somewhere to test. If that gets the light working it needs the contacts cleaning up. This has worked for me over the years. If it’s a 2 wire job then there should be a switch built into it which is probably faulty. Hope that’s useful for anyone else in future.