what\'s this thing?

[L18M]

i\'m guessing its a 5 pin relay from reading other posts on rx7club. maybe its for the pre-amp?
anyone running the stock audio?

[1990_fc3s_t2]

i think if it was audio related it would be on all ecu\'s:3Confused

[grinder]

hummm if thats the pre-amp ( IF ) then it might only be in convertables - as they came with the fancy speakers in the seats

[rx7pat]

I have a JDM TII and I have never seen one of those on my ecu :3Confused

[Easy_E1]

Looking at the factory (US) wiring diagram for the 1987 FC,, the only thing in that area is what Mazda calls an "Atmospheric Pressure Sensor" But it only has a 4 plug connector.
 
Now the "Knock Control Unit". It has a 7 wire connector and it\'s right next to that. Not giving a good view of the part though.

[Brett]

To my certain knowledge no UK spec car has one, or the facility to have one. I\'ve had one on the side of every JDM ecu i\'ve purchased though. I did open one up about 5 years and there\'s nothing clever in there that makes me believe it\'s any sort of controller etc... Can\'t really remember now.
IIRC the (earlier >88) uk egi\'s have the dim/dip relay located above the ECU on a sub plate beneath the glove box, so might be something like that.

[pdtaylor18]

Only found on the JDM car and does nothing. I have had these plugged in or left unplugged and they seem to do nothing.  I thought it was something to do with air con as the ECU needs to know when its on for the fans.  Its nothing to do with audio or atmosperic pressure.

[pdtaylor18]

In fact it is the coolant control module so my guess it is to do with AC as this was on all JDM cars and maybe only a option on UK cars. I dont think I have even seen a UK car with aircon. On my FC I have kept the small AC fan as a backup to my main rad electric one as this will still come on above certain temps or when I press my AC switch. (even though I have ripped out the aircon).

[grinder]

AC was an option on the UK cars - when i bought my black TII - the owner said that when he bought it - it was an option he could have had

my Cab has AC - so thats prob why i have that box of tricks

[m1tch]

I have only seen these on JDM chipped ecus, so it might possibly be a built in FCD? Also the N374 ECU is the knightsports on that has no rev limiter on it, so it could be something to do with that?

[grinder]

I thought the N374 was just a stock JDM ecu ?

[pdtaylor18]

In fact it is the coolant control module so my guess it is to do with AC as this was on all JDM cars and maybe only a option on UK cars. I dont think I have even seen a UK car with aircon. On my FC I have kept the small AC fan as a backup to my main rad electric one as this will still come on above certain temps or when I press my AC switch. (even though I have ripped out the aircon).

I\'ll quote myself as this is the coolant control module for the electric fan.

[Adam fc]

Ive been wondering what that was when i got my redom ecu of liam,