DIY: Custom Retro Switches

This mod is fairly popular for anyone going for the retro mx-5 look. Nothing says retro more than toggle switches, plus the stock switches on the NA tends to build carbon deposits on the contact points resulting in the switches not working. Embarrassingly, it has happened to me a few times when someone was checking out my car. This window switch idea came from a bloke in the UK. Check out his site here for more details on wiring and design.


Anyway, here are the stuff you’ll need. I’ve also linked some Jaycar pages where you can buy some of the parts. This project is fairly time consuming. Took me about 2 hrs in total to fabricate. It may have taken longer, but thankfully, I have a workshop with all the spare parts and tools at work which I could “borrow”. 😛


  • 1 stainless steel plate, cut to a rectangle 66x52mm. It should just cover the stock plastic window switch. The corners are similar size to an Aussie 10 cent coin. Check the radius as you are filing down the plate. You can buy this at Bunning’s.
  • 2 toggle switches.  You will need Double Pole, Double Throw (DPDT), ON/OFF/ON momentary switches.  Here’s a link to where you can buy some.
  • 12 ring or fork crimp connector. I had some lying around the workshop but again here’s a link to where you can buy some.
  • 10 gauge automotive wire.
  • 1 Mazda MX5 plastic window switch. Feel free to buy one from ebay if you do not want to cut up your current ones.
  • 4 nuts and bolts. Had some nifty hex bolts lying around, but any bolt from Bunning’s should do the trick. Really depends on personal preference.


  • Soldering Iron
  • Hack Saw
  • Range of files
  • Sandpaper
  • Drill
  • Crimper
  • Phillips-head screw driver
  • Hex key and spanner
  • Dremel


Using the dremel I hacked out everything on the switch. Take care when cutting the hole as you don’t want to cut/weaken the three mounting points on the plastic backing. Don’t worry too much about cutting a nice straight rectangular hole, the metal backing will cover the hole. Just make sure that it’s big enough to fit the toggle switches (I’m just a bit anal about shit like this).


Next, cut out the metal plate to size and use a file to shape the corners. Obviously sand the corners as well, if you like, sand the surface for a brushed look. Since the switches have been hacked, this make it very easy to check if you have the correct dimensions. It helps if you draw a mock up plate out of paper/cardboard to make sure everything fits.


Then, hold the metal plate against the plastic holder and drill through the two pieces with the desire hole size for your bolts. This ensures that when it comes to assembly, everything fits.  perfectly. Where you drill the holes are completely up to you.


Finally, crimp and solder everything together. Remember to put heat-strink on all your connections! I found 10-guage wires difficult to solder strongly, but I stumbled on this  very helpful video on soldering thick gauge wires. Alternatively, you can use flux if available. Here is the wiring diagram.



Then all you need to do is assemble and you’re done!


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