i have an 89 rx-7 there is this mystery plug on my ecu harness i cant figure what it belongs to. Its the only black round plug on the whole harness it branches of the wiring harness with the primary injector wires and the water temp. i only has one single metal contact.the wire golor appears to be green black with red dashes. HElLP!!!:-) see ya all later thanks

 

I would need someone with a TII to confirm this, but I think its the plug for the knock sensor. Every 89-91 n/a I have ever seen has one unused plug inthe wiring harness. Same plug as the O2 sensor, right? I think the TII's and n/a's use the same engine wiring harness. The n/a ECU just doesnt have a pin for that wire.

 

well thats good to hear

i must've spent an hour searching for a sensor or anything to hook that damn thing up to when i was putting my motor back in my car. then i just said to hell w/ it and crossed my fingers.

 

89-91 TII's and automatic FC's have an auxiliary electric fan in front of the A/C condensor. There's a water thermoswitch in the back of the water pump that send s a signal to a relay to turn the fan on. The plug is for the water thermoswitch.

 

86-88 RX-7's with the electric fan have the thermoswitch on the water neck coming off of thye water pump.

 

thanks fellas (or ladies just in case there are some out there P.s. if there are any females around 20 whole like sevens CALL MEH:-) ) see ya

 

who* :-P