How to replace the headlight bulbs on an MX5 MK1 (NA).
I have Halogen headlights, these take an H4 bulb.
With the bonnet up, headlights off (for more than 5 minutes as they get really hot), and headlight maintenance button pressed (middle of the dash next to the hazards), you can remove the four screws holding the black cover on.
Pull the cover off carefully once the screws are out, it might catch on something but nothing else should be holding it on.
After the cover is off you can see the lens and bulb in a mounting that is held down by some screws loaded on springs.
Loosen the (three) screws up until you can turn the mounting such that the heads of the screws pass through the larger section of the holes.
Disconnect the power from the back. Then take off the little black hat (insulator?) - nothing is securing this it’s just a snug fit and will pull straight off.
The metal clip securing the bulb can be removed, the old bulb lifted out, and the new one installed (don’t touch the glass).
I’ve put the new bulb in, reclipped the metal clip, and put the little black hat back on really snuggly.
The new bulb should only fit one way.
I’ve installed Osram Nightbreaker Plus bulbs, these claim to be 90% brighter and they do appear to be.
Everything went back in the way it came out and obviously both bulbs were replaced.
The biggest difference though seems to have come from cleaning the lenses (just soap and water).
Finally its worth mentioning that I’ve pretty much guessed this process and it may well be wrong (although I don’t think it is). Don’t blame me if you destroy or damage something..