Before You Start / Safety
This guide is for Mazda MX-5 NB (1998-2005).
Mis-aimed lamps are a safety problem both ways: too low reduces seeing distance, too high blinds other drivers.
- Work on level pavement facing a flat wall/garage door.
- Set parking brake and keep car from rolling.
- Perform with normal road-use weight (typical fuel/load).
Required Tools
- Tape measure
- Painter’s tape or chalk
- Tire pressure gauge
- Screwdriver/socket for lamp adjusters
- Marker pen
Where the adjusters are on NB headlights
On most NB lamp assemblies, adjusters are accessed from the rear/top of headlamp housing area.
Practical identification:
- one adjuster changes vertical aim,
- one adjuster changes horizontal aim.
Turn slowly and watch beam movement on wall; if adjuster spins freely with no beam movement, internal adjuster hardware may be stripped.
Pre-aim setup (do this exactly)
- Set tire pressures to normal spec.
- Remove unusual cargo from trunk/cabin.
- Fuel around half tank is commonly used in aiming procedures.
- Bounce each corner lightly to settle suspension.
- Ensure lenses are clean and bulbs correctly seated.
Wall method (practical baseline)
1) Initial mark at close distance
- Park close (about 1 m / 3 ft) to wall.
- Turn on low beams.
- Mark on wall:
- vehicle centerline,
- center of each low-beam hotspot/cutoff reference.
2) Move to aiming distance
- Reverse straight back to 25 ft (7.6 m) from wall.
- Keep steering straight and vehicle square to wall.
3) Create target lines
- Draw a horizontal line at original lamp-center height.
- Draw a second line about 2 in (50 mm) lower as a common low-beam baseline at 25 ft.
- Keep vertical centerlines for left/right lamp alignment.
Note: local legal targets can differ. Use this as practical baseline, then fine-tune to legal/FSM requirements for your market.
4) Adjust low beams first
- Adjust vertical so cutoff/hotspot aligns near lower target line.
- Adjust horizontal so beams are centered and balanced left-right.
- Make small changes and recheck both lamps together.
5) Verify high beam relationship
Check high beams after low-beam setting:
- patterns should be balanced side-to-side,
- no obvious skew from one housing.
6) Road validation at night
On a dark road:
- confirm good forward distance,
- avoid excessive foreground-only brightness,
- confirm no frequent oncoming flash complaints.
If aiming won’t hold or won’t move
Inspect for:
- stripped adjuster screws/gears,
- cracked reflector mounts,
- mixed aftermarket/OEM housings with mismatched mechanisms.
Repair hardware first; repeated adjustment attempts won’t fix broken internals.
Verification / Post-service checks
- Beam pattern stable over bumps
- Symmetric left/right cutoff behavior
- Improved visibility without obvious glare complaints
- Recheck after suspension or front-end work
Sources
- MELLENS — Mazda Miata Factory Service Manuals (year/VIN headlamp adjustment reference source). Retrieved 2026-03-15. https://www.mellens.net/mazda/index.html
- Daniel Stern Lighting — Why & How to Aim Headlamps and Auxiliary Lamps (aiming sensitivity and rationale). Retrieved 2026-03-15. https://www.danielsternlighting.com/tech/aim/aim.html
- Popular Mechanics — How to Adjust Your Headlights (practical wall-aim setup context). Retrieved 2026-03-15. https://www.popularmechanics.com/cars/a63828996/how-to-adjust-headlights/
- Reddit r/Miata — Search: nb headlight adjustment (NB owner reports on adjuster failures and housing variation context). Retrieved 2026-03-15. https://www.reddit.com/r/Miata/search/?q=nb%20headlight%20adjustment&restrict_sr=1