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Upgraded 80A main relay for NA/NB

Yours may be green or black.
Upgraded 80A main relay for NA/NB
Replace your main relay with this 80A unit.

Availability: On backorder
You can place an order now and we'll reserve it for you. We are expecting the parts around July 4th, 2020.



The main relay powers your ECU, fuel pump and your ignition system, amongst other things. And when they fail, you're stuck. It's a mechanical relay, and after a couple of decades they just get tired. Higher power fuel pumps will also draw more current and will hasten the failure.

Typical failure is immediate. The car will be working fine, then it simply won't start. This will strand the car wherever it sits - at a restaurant, at the beach, in your garage. We've even seen them fail mid-drive, which just shut the car down. Once the relays fail, they almost never come back.

Luckily, it's an easy fix. Swap out your relay as preventative maintenance or toss a new one in the glovebox. When you do remove the original, take a good look at the condition of the socket in the fusebox. If it's corroded, we recommend cleaning it to prevent a recurrence.

This particular relay is an 80A unit that's able to handle higher current than the stock relay in most Miatas. It's the stock part in 1990-95 models, replaced by a downgraded version in later cars. This makes it a good choice for cars with upgraded fuel pumps. It's more expensive than our lower amperage unit but it costs less to buy a better part than it does to burn out an underspecified one over and over! For cars with really high fuel pump draws or that cannot take the chance of a failure, look at our Trackspeed fuel pump rewire kit.

Mazda part JE16-18-811. Fits all NA and NB Miatas.

Additional Information

Additional Information

Part number M36-80310
Fits: 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1999, 2000, 2001, 2002, 2003, 2004 (non-MSM), 2005 (non-MSM), MSM
Manufacturer Mazda
Flyin' Miata exclusive No
Fits Exocet? Yes
Proposition 65 Warning: Cancer and reproductive harm
California emissions No information at this time

Customer Reviews 4 item(s)

Exactly what I needed.
Fixed my issue immediately! Normal day drive turned into a tow after parking for a bit. Car is a 94 and has around 200k and is supercharged (extra heat).

Naturally I pulled the fuel pump first and generally took the car apart. No power was getting to the ECU or the fuel pump.

PRO TIP: Turn the ignition on, if you don't see the ECU and ABS light up on the dash then this will fix the issue.
Review by Andre / (Posted on 11/13/2019)
SMP Relay
Unfortunately, Jason's advice on the SMP RY288 is incorrect. That relay is rated at 20 amps.
Review by Fourvalve / (Posted on 8/10/2018)
Save your money
I know this is a Denso relay; and thusly, the OEM replacement, but SMP makes the RY288, which a direct replacement for this, and is $25 cheaper on RockAuto.
Review by Jason / (Posted on 4/13/2017)
Replacement instructions
This is the main relay. 80 amps. Everything else depends on this. If you have no power in the fuse box, this is a good place to start. Location is in the fuse box. For removal instructions, try this URL. There three clips that hold the relay in place. Two on the short sides one on the 'engine' side. One of these can be released with a small screw driver. The others come lose by wiggling the component side to side. I know that's not very satisfying, but Mazda did not intend for this part to be replaced very often. A little 'dielectric grease' on the contacts is a good idea, going back in.
Review by Maneki Neko / (Posted on 3/16/2017)
Instructions for this part are not currently available online.

Why stop here? Consider this upgrade.