[Guide] Fitting Running/Side Marker Lights To Mazda MX5 NA

Mazda mx5 side marker lights

Fitting running/side marker lights to your Mazda MX5/Eunos Roadster is a subtle mod to make your car stand out a bit and increase visibility to other road users, it's also ridiculously easy to do yourself even if you have never worked on car electrics before.

US spec cars have orange running lights in the front and red running lights in the rear, however UK and JDM spec MX5's have reflectors instead.

Fortunately for us it's very easy to fit bulbs in these reflectors and wire up the side marker lights to be come on with the side lights.

Tools needed:
  • Cross head screwdriver
  • Wire strippers/cutters
  • Crimping tool
  • Drill
  • Large flat head screwdriver
  • Pliers


Parts needed:
  • 2 x 501 (W5W) bulb holders
  • 2 x Amber 501 bulbs
  • 4 x Cable Lock (Scotch Lock) Connectors
  • 4 x Butt connectors
  • 2 x cable ties
  • Electrical tape
  • 8amp wire

Step by step guide
Remove side reflectors and make hole in the rear to fit bulb holders. To remove them just undo the two phillips screws on either side and then gently pry out.

mazda mx5 side marker reflectors

The only difference between the UK and US side reflectors is that a hole was not made in the rear. So all we have to do is make that hole.

501 w5w bulb holder

Use something to measure the diameter of the bulb holders so you know how big to make the holes. The plastic is very soft so go slowly and no need to put much pressure on the drill, you don't want to fly through and damage the lens.


My bulb holders were about 13mm and I didn't have any drill bits that big, so I just went as big as I could and then gradually increased the size of the hole with various flat head screwdrivers. This worked very well as the plastic on the rear of the side marker is very soft.


You want a nice tight fit so the bulb holder doesn't fall out and water and dirt can't get in. You can secure the bulb holder with silicone or similar but I wanted to make it easy to change the bulbs so chose not to do this.

Remove sidelight/indicator unit and thread wire through to wheel arch

Mazda mx5 Miata side light wiring

Again just two phillips screws to remove the sidelight, both bulb holders twist to unlock.


Pop up your headlights and there's a few holes to feed the wires down into the wheel arch directly under the headlight. I routed the new wires under some of the original wiring to keep it tidy and stop it from flapping around.

Fit cable lock connectors to positive and ground from the side light


The good thing about the cable lock connectors (also known as scotch locks) is that you do not need to cut any wires to tap into the connection. Watch out that both wires are centred in the connector to ensure a good connection is made.

Connect bulb holder to new wiring


The 501 bulb holders that I bought came with approx 7cm of cable so this needed to be connected to the new cable I just installed. To do this I used bullet connectors from Halfords as a temporary measure however I am intending to solder and shrink wrap this connection as that is a more permanent solution.

Fit amber bulbs and refit reflectors


You want to check at this point that everything is still working as it should. Sometimes the scotch lock connectors can be a bit temperamental. So give everything a good wiggle and tug to make sure it's not going to lose a connection as soon as you go over a pothole.

Secure wire with cable ties


Your bumper should have this bracket in it which is ideal for securing the wires to stop them flapping around in the wind.

You're done



Like this guide? Spotted that i've done something really dumb? All comments welcome below.

1 comment :