I can't find where this wire goes in the engine. It's black with red line on the engine side and I traced it to ecu pin-out 1A but the wire is different color inside the car (blue with red line). I am also suspecting it has something to do with the relay circled in the pic. Does anyone know what that wire and that relay is for?

 

If that's the harness that plugs in to the ecu, I believe it is the coolant level disconnect. I believe it hooks up the the coolant lvl sensor on the front of the water filler neck.

 

No it's not the coolant level sensor that's already connected.

 

I'm almost positive it's the "water thermoswitch"

from what i remember this doesn't even go back to an ecu pinout. its like a wire that enters the harness in the engine, and exits the harness in the engine to connect to something else. I know this is vague but go to this link:
https://www.rx7club.com/3rd-generati...arness-865669/
and also take a look at a single turbo harness conversion how-to.
Even if you're not converting it for single turbo, there are still good pictures that will be helpful.

There aren't many connectors on the ecu with one wire.

 

It doesn't go to the ECU as that pin is a 12V source. Its the thermoswitch which activates the last resort fan speed.

thewird

 

Thanks for the replies guys.

thewird, 1A is that exactly, it says in pinout 12V with 7.5A fuse.

http://www.rotary-imports.de/space/PFC_install_FC.pdf

So it goes to the back of the ecu, but what do I do with it inside the engine bay? Leave it like that, not connected to anything?

Also can anyone tell me what relay is it in the pic (circled with green)?

 

All 4 of those relays are for the fans. We already told you the connector is for the thermoswitch lol.

thewird

 

ok cool, thanks again.