This is a Mazda MX5 Hyper Flash Fix. This is to stop hyper flashing of indicators once you have changed to LED lights on your Mazda MX5 Miata. This fix should work on all Mazda MX5 Miata Mk2.5 NB2 2001-2005.
As part of my MK Indy kit car project I changed all of the indicator lights to LED lights. This made the indicators then hyper flash too quickly, so I needed a solution to fix it. My donor vehicle is a Mazda MX5 Mk2.5 NB2 2004 model.
There is a seperate thread with a solution for Mk1 and MK2 MX5 Miata which have a different flasher Unit. This is described here.
Why does it Hyper Flash?
Standard incandescent bulb circuits rely on the natural resistance in the bulbs to control the speed of the flash. If a bulb blows, the resistance reduces so the indicators start to hyper flash. This is designed to be an obvious sign to the driver that a bulb has blown.
So, when you replace the indandescent bulbs with LEDs which have a much lower resistance the circuit hyper flashes all the time.
How to Solve It
To solve this, we need to add more resistance back into the circuit. A crude way of doing this is to purchase some high-power resistors and add them in series with each indicator. These devices add complexity to the circuit and generate a lot of heat. So this was not an ideal solution for me.
I researched my options using the flasher part number 3211-215-320 in my search. I finally found this post on a MEV Exocet forum. This has a very brief description of how to solve the problem. I have expanded this solution below to help guide anyone else to do it more easily.
Open up the Flasher Unit
Open up the Flasher Unit using a small screwdriver. Prise open the tabs on either side and you can separate the flasher Unit into 3 parts.
Add 10-ohm resistor
The fix is to replace the bent metal wire (which is a shunt resistor) next to the 2x small relays with a 1W 10-ohm resistor and solder it in place.
I’m not sure of the power that is actually used for this part of the circuit. So I have just used the same rating of resistor as the post above. This seems to work. A pack of 10x resistors cost me £2.50 from eBay so a nice cheap and easy fix.
Summary
Adding a 1W 10-ohm resistor into the circuit reduces the flash rate to a normal level for the IVA test. A very simple Mazda MX5 Hyper Flash Fix, which is much better than using inline resistors.
