87 rx7 Turbo II
Rtek 1.7
I didnt change anything but was driving to work today and my guages died but the car kept running. Looked to the floor where the ECU is and It was smoking slightly so I parked the car. After work I decided to take a look in depth. Heres what I discovered.





The white wire appears to be the problematic wire. Idk I might try cutting it just to see if something stops operating or the problem stops...

If anyone knows what the white wire is before I completely dissect the wire that would be great...

 

If the wire is plain White w/no stripe then it might run to the Split Air Solenoid which is screwed into the ACV. You could unplug this plug (has but two wires) at the ACV and perform a continuity test to confirm if it is just that wire. The solenoid is not vital at all but is an emission related item.

 

http://wright-here.net/files/manuals...ingDiagram.pdf.

 

I hate looking through wiring diagrams when its part of the main part of the loom gives me headaches... The solenoid was disconnected as it is however I wonder if the wires within the connectors were touching causing the short but theres no damage on the ends of the prongs. Ive decided to cut the problematic wire and see if it changes anything.

 

If the problematic wire does run to the split air solenoid well it doesn't receive power from the solenoid as the power comes from the ECU so in this case cutting the wire would do you no good.

 

I traced it to the connector in the car which may or may not be the source of the problem but im having a hard time telling where this wire starts or ends. As far as I know its something regarding the emissions harness.




This is the pin affected if im not mistaken...

 

The White wire at the split air is fed voltage by the ECU via the Black/Blue wire. So, if the White wire is still plugged into the B/L wire then that part of the White wire is still receiving voltage w/key to on even if the White wire is cut. If you want the voltage from the B/L wire to stop making its way into the Emission harness then you need to stop it before it reaches the plug.

 

okay so I need to find where it ends closest to the ecu and clip it and probably replace the whole wire just to make sure its not shorting at all or just delete it.

 

The wire from the ECU runs to the plug you provided a picture of. You could just remove the pin/wire from the ECU plug (pin 1I).

 

okay and I dont need this wire at all if emissions are irrelevant right?

 

I wouldn't think so.

 

Im having a hard time finding a diagram for the pins that go into the ecu. Would you happen to be able to tell me which is pin 1I

 

https://www.rx7club.com/2nd-generati...iagram-968998/

 

While I was removing the wire, I noticed that the wire splits in two different directions. According to the diagram its the 5th gear switch. So I have a couple of questions...

Why does the wire split to 2 different directions?
(The one goes up to the connector then becomes white and goes through the firewall. The other one goes up underneath the heater core.)

Would this wire being faulty attribute to my car having a hard time maintaining a speed in 5th gear?

Where does each line end?

 

Oh and I've never could get the reverse lights to work but I always thought it was because the switch itself is disconnected. Maybe the wires are tucked somewhere and causing the short? Where are the wires supposed to run?

 

When you place the car in 5th gear w/key to on the voltage on the B/L wire should have 2 volts. Before this the B/L wire should have 12 volts. This would tell you if the 5th gear switch is working or not. The shift up lights working would also tell you if the 5th gear switch was working properly. When the car is in 5th gear and things are working accordingly the split air solenoid is activated and extra air is sent to the converter. Also, the timing is altered and leans out the afr's so as to improve gas mileage while in 5th gear.

You should have two wires on your transmission related solely to the reverse light switch. One wire is B/Y and is powered by the Meter fuse. The other wire is Red/Green and runs from the switch to the reverse lights. W/the car in reverse the R/G wire at your reverse lights should have 12 volts to them. If they do and the reverse lights don't work then make sure that both filaments in the bulb are good as they are dual filament bulbs.

 

Reverse lights are 1156's...single filament.

 

Whoops!

 

Okay so I'm going to have to address this mess...


5th/reverse button not even connected...


These wires maybe have something to do with it?

 

The R/G and B/Y wires are for the reverse switch while the other two wires, Black wire and B/L wires, are for the 5th switch. And as stated earlier, the B/Y wire of the reverse switch is powered by the Meter fuse, which also powers the gauges, so if this wire grounded out it could cause the Meter fuse to blow and then there goes the gauges.

 

The reverse switch and the 5th switch are one in the same right? It only has 2 prongs though? Is this the wrong switch or am I missing something?

 

Not the same switch as they are different but are grouped together though. What you have pictured might be the neutral switch.

https://www.rx7club.com/2nd-generati...ensors-776759/

 

Any Comments on Rising RPM - Product - IAC Manifold
Im thinking it might be a quick clean solution for my current IAC.

 

Where does the white wire turn into the black and blue wire that connects to a switch?

 

The B/L wire which leaves pin 1I runs to FE-02 which mates w/another B/L wire which then runs to the 5th Switch. FE-02 is located near the trailing coil/Main Relay area.
FE-02 is the same plug which has the Yellow/Red wire that comes from the Oil Pressure Sender. And this plug has 6 pins but probably only has 5 wires in it.