This is my first post on HT, normally I search for hours and eventually find some tidbit that helps me solve the problem but it's been a week and I'm at a standstill so I finally registered
B18B1 motor, GSR ITM and IACV, PR4 OBD0 ECU, YS1 LSD tranny, 91 EF hatch.
Rescued this beauty from a couple of, ahem, not-very-developed-individuals for $900 and the morons had cut almost half of the wires from the harness.
I've managed to piece most of it back together, and tuck it simultaneously, but the IACV plug is gone, so I'll have to solder straight to the pins, but I'm unsure of which wire goes where.
There's a black/yellow wire and a blue/yellow wire.
One closer to the ITM, another more towards the firewall.
If someone could pop their hood, check the wire colors respective to their locations and post it here, that would be awesome.

Secondly, the ECT wires are cut 2" from the plug, and the wires from the harness are gone. One wire is blue/yellow, the other is black/yellow. One of them goes to C6 on the ECU, where does the other go to? I read somewhere that all blk/ylw is switched 12v, is that correct? If so, that would mean the blue/yellow goes to C6 and the other goes to switched 12v but where do I find that on the ECU? A17?

Finally, the radiator fan plug was cut as well, so I'll need to solder the wires where they need to be. I've figured out black=ground and blue=positive(no brainer) but I'm not 100% where they should be connected in regards to the ECT.
I came across a wiring diagram somewhere on here in regards to an Integra RS, and it showed; ECU - ECT - Rad Fan - +12v 15a fuse.

From what I understand, this would mean the ECT grounds out when the coolant reaches a high enough temperature, allowing the fan to ground through the ECU (I assume pin A11, after reading here that it's a computer controlled resisted ground) and completing the circuit, turning the fan on.

If I'm wrong, feel free to correct me. No, I can't just get a new harness, I've managed to fix this one remarkably well and the engine runs because of it, but overheats due to what I assume are the ECT and rad fan not turning on. Also, CEL code 14 (IACV). Thank you guys so much in advance for the replies.

 

57 views and no replies? Where are all the wiring gurus?

 

IACV = black/yellow is closer manifold
blue/yellow closer to fire wall

ECT = red/white and green/white
red/white goes to c6
green/white is a shared ground that splices together with TPS, IAT and ECT
all connect to c12

Radiator fan switch = green and black wires
green goes to ecu B4 and Radiator fan relay

these are the factory wires. you can download the factory shop manual. the switched 12v sensor is the IACV and NOT the ECT.

 

radiator fan wiring diagram

 

Spectacular guys, thank you. One problem with the IACV wiring though; somewhere on here someone said one of the wires goes to A17, but I don't have a wire at A17. Where does that wire go? 12v?

 

IACV has 2 wires, black/yellow is power, blue/yellow goes to ECU pin A11

 

here is where you tap into for the 12v power for iacv. you have 2 options:
1. stock option on 88-91 Civic/CRX is its located on the white plug on the passenger shock tower along with another black/yellow wire that ties into the alternator. if you look at the plug you will see 8 wires, looking at it from its stock location it is the bottom row wire #4.
2. on 92+ civic/integra the iacv is tapped into the 12v junction block (plug that is blocked off on 92+ driver shock tower all yellow/black wires). or you can run it straight through to the ecu and tap into a13 or a15 on obd0 ecu plugs.

 

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