2010 NC 3.5 front sidelights not working

  1. My model of MX-5 is: NC__
  2. I’m based near: Salisbury__
  3. I’m looking for technical help or recommendations on: front sidelights not working__

New to forum so may be not using it properly
Anyhow - I have an NC Mk3.5 2010 reg and it is due it’s MOT in a couple of weeks. I have done all the usual checks and the only thing not working are the front sidelights. The rear lights, number plate lights and instrument lights are all Ok and the fuse is not blown. I have changed both bulbs for new and still nothing .Has anyone come across this before, and does anyone have a quick fix which doesn’t involve dismantling the front end to get at the wiring please

As far as I can make out, the side lights are on the same circuit as the rear tail lights and number plate light. So you may have to start delving in to the wiring. I suppose you could cheat and run a fresh wire from the back to the front to at least get it through the mot. I’ll have a look, through the service manual nd see if I can find anything obvious.

i dont have a wiring diagram for 2010, so wiring colours may be different.
On the 2007 diagram, all the side light components share a green/black wire.
Both front sidelights have their own earth, so you can rule out an earth problem.
so a potential break somewhere in the green/black.

Manuals can be found here. https://www.mellens.net/mazda/

And if you do decide to cheat and run a wire, maybe consider going down the drivers side.
On my 2005, there’s a grommet somewhere near the pedals which makes running a wire into or from the engine compartment easier than going in from the passenger side.

I am not an electrical person. If the sidelights have their own earth why can I rule that out as the cause of the problem? If the earth was not good then lights would not work? And how do I find a break in the cable , sounds pretty daunting!

Left front sidelight has a different earth (behind the left headlight “combination light”) from the right front sidelight’s earth (behind the right headlight “combination light”).

It is less likely for these two separate earths both to fail (two problems) than the common 12V wire feeding them having a single problem.

If you are having problems with electrics, it is probably best to ask a professional to have a look.

This is what I was getting at. If one earth failed, then one side wouldn’t work, but for both earths to have failed would be unlikely, or unlucky. So the fault is more than likely with the green/black. (Live feed)
Finding the break could be obvious or something almost impossible.
Whilst a bit of a bodge job, but scotching into one of the rears and feeding this to the front and scotching in to one of the side lights might be the simplest solution.
If you have access to a multi meter, I’d start by checking the terminals inside the bulb holder. Confirm if you have earth and then test for 12v.

Do you know if someone in the past has done a DRL conversion or something and messed with the wiring? Does it all look original wiring around engine bay/head lamps.

And you are sure that the replacement bulbs that you fitted are OK aren’t you?

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Many thanks for all the advice. I have an auto electrician booked for early February but was hoping this might be a common problem and someone might say “just do this and this” thus saving the budget! It would appear it is all trickier than I thought and hopefully an accessible break in the cable will be found and patched. Will let you all know what happens when it happens.

Update - always helps if you know which the sidelights are and if they have bulbs in the holders. Difficult to get at but all sorted now. Almost as good as “have you checked the fuses?”