Changing the thermostat on an NB / NBFL is a quick and easy job.
The only tools you need are:

12mm socket
13mm socket
Philips screwdriver
Pliers
Lithium grease
New thermostat
New thermostat gasket (recommend Mazda OEM)
Catch tray and cloths to clean up spilled coolant

****...

There is so much crap out there on this subject for something so simple.....Yes if you press the A/C it should trigger both fans??? now that is all well and good "IF" your A/C works??? Or your pride and joy was built with it as most UK spec Mx-5's are not, or it has been removed from your...

Tools needed...
1/4 drive ratchet, 10mm socket and extension bar,
Pointed pliers, pliers, or hose clip pliers,
Utility craft knife,
Silicon spray lube,
New hoses, supplied by Autolinkmx5 for this guide.

Should take a hour ,but there are no medals for rushing any job...

********Health and safety...

This "How to Guide" will cover adding an A/C fan to the existing radiator cooling fan thereby giving dual cooling fans for far better radiator cooling (A/C = Air Conditioning)

If your Mazster was not built with A/C then this is a great upgrade and also for those ripping out their A/C it...