Wiring Harness Questions

WagoneerWagoneer Band Wagon
in Electronics, Fueling & Air Conditioning
Hey there I was wondering if someone could fill me a bit here. I have a 1989 civic wagon. I just pulled the engine and brought it to the junk yard were they took it and pulled one from a wagon in there lot to give me. So the engine is in and I just realized that there are different wiring harnesses on the engine. My new engine has a circular one. one has more wires than the other one. Is there a easy adapter for this? Can someone tell me what wires I need to run? Any information & suggestions on this issue to make my life easier will be very appreciated. Thanks

Comments

  • JakerJaker familEE
    Get your 1989 engine harness back form the wreckers. The work invloved in changing the harness you have now will be huge.
  • bam-bambam-bam Council Member
    was the engine from another '88-'91 civic? Is one DPFI and the other one MPFI? If one of the 2 wagons was 4wd and the other one not the engines (and wiring) are different. Please post pictures and we'll try to steer you along.
  • skinnyskinny Senior Wagonist
    Yeah mpfi is the way to go. If you really wanna be gangster get the wire harness from a ex and start swapping in all the power options lol. It's not hard to go from dpfi to mpfi it's just a pain and requires some adapters from rywire. IMHO I would just swap out the dash and engine harness.
  • WagoneerWagoneer Band Wagon
    The Engine is a 6 pin square and the one coming off the body is 8 pin and circular. What does this mean? Why would they change the harness on the same model car with the same engine? I will try to get some pictures. Thanks
  • bam-bambam-bam Council Member
    6 pin square? On which side of the engine? Is the square plug gray?
  • WagoneerWagoneer Band Wagon
    Here is a picture.....
  • WagoneerWagoneer Band Wagon
    The Car is a 1990 RT4WD, but I have no idea what year the new engine came out of.
  • skinnyskinny Senior Wagonist
    Show us some pics of the engine itself. Include the intake mani exhaust manifold distributor. This will help us a lot. It looks like you may have gotten a pre obd engine. Do the wire colors match up on each side of the plugs
  • bam-bambam-bam Council Member
    skinny wrote:
    Show us some pics of the engine itself. Include the intake mani exhaust manifold distributor. This will help us a lot. It looks like you may have gotten a pre obd engine. Do the wire colors match up on each side of the plugs


    skinny, look at the engine bay pictures in Charb's "Jane" thread. His has a plug like that on the LH side. Is it an '88 thing?
  • Okiewagon1Okiewagon1 Wagonist
    This is very common. You picked up a 88/89 engine harness and will need to make a conversion plug to make this work or depin the square plug and repin into a round plug. You will notice that all of the colors will match up just fine. I dont remeber if the extra two wires were even needed or not I will have to check my notes.
  • JakerJaker familEE
    Like I said above, go back to the wreckers with the engine wiring harness you got with your new motor, tell them you need the harness from your old motor because the harness they sold you doesn't fit your chassis, and they'll likely swap it around for you. You could be done by now.
  • bam-bambam-bam Council Member
    Jaker wrote:
    Like I said above, go back to the wreckers with the engine wiring harness you got with your new motor, tell them you need the harness from your old motor because the harness they sold you doesn't fit your chassis, and they'll likely swap it around for you. You could be done by now.
    Yeah, I suggested that in pm, he said it was already gone/ couldn't get it.

    Okie: I didn't know that about '88-9 harnesses.

    OP: where are you located? If you can't come up with that plug body locally, I can send you one.
  • WagoneerWagoneer Band Wagon
    Where can I buy a conversion plug. It will be very hard to find one around here. Thanks
  • skinnyskinny Senior Wagonist
    shouldnt be hard to make a conversion harness. Its pretty easy to repin
  • WagoneerWagoneer Band Wagon
    So once I get the harness thanks to Bam Bam, I will re-pin it. Two questions, first what are the two extra wires used for? Second will I need to run those wires and hook them up? does anyone have a wiring diagram? Thanks
  • WagoneerWagoneer Band Wagon
    bump
  • bam-bambam-bam Council Member
    What color are the 2 extras? Let's try to name them all:

    yellow
    red --injectors
    brown
    light blue

    yellow/black --injector power




    that leaves 3 more, let's fill in the blanks
  • WagoneerWagoneer Band Wagon
    There's blue with a yellow stripe.

    The colors of the two extra wires are black/yellow and blue. What do these wires go to? I was told that one of the wires possibly controls an idle control valve...The engine being swapped is one with a PGF-I intake manifold. What is this 1988 engine missing on it that my 1990 engine had? what do I need to do to make this work?
  • WagoneerWagoneer Band Wagon
    bump
  • WagoneerWagoneer Band Wagon
    I have two have this car out of my buddies garage by the end of the week! can someone please help. I need to find out what these wires go to. Thanks
  • SikocivicSikocivic Wagonist
    Wagoneer wrote:
    I have two have this car out of my buddies garage by the end of the week! can someone please help. I need to find out what these wires go to. Thanks
    I realize that you are in a bind. The problem is that you are trying to do something that is the wrong way to do it. I don't even know if it will work at all. I am just saying that you should not be surprised that nobody can help you when you are trying to do something the wrong way.

    I found this link. Maybe you can find something in here that will help.

    http://www.fourthgenhatch.net/mpfi.html
  • vtecn8ivevtecn8ive Senior Wagonist
    black/yellow is probably for the resistor box, should be the 12v source.

    blue wire may be for fuel injector (off the top of my head).
  • bam-bambam-bam Council Member
    I'm bumping this old thread because I'm now in the same predicament.

    I bought my 1989 RT without an engine or harness, and have been unable to find a '89-'91 engine harness. I did find an '88 harness, and since I'm changing things around for the SC and converting to OBD1, I figure it's close enough.

    I'm running into the same thing: the '88 had a 6-wire square plug at the left shock tower, and the '89 has an 8-wire round. I've identified all the wires.

    red-inj.
    lt.blue- inj.
    yellow- inj.
    red- inj.
    yellow/black- injector power
    blue/yellow- EACV
    black/yellow- Fast Idle Control Valve
    dk.blue- FICV


    Edited to show what I found out after poking around at several cars here at bamtech...

    The '88 manifold does not have the fast idle valve on the back of the intake, however the '89 manifold on pebbles' wagon does. And the wires on said valve are dark blue and black/yellow. (It's not hooked up on her '91 DX, which was MPFI converted with '89 Si parts)


    There are also some wires to be repinned at the other shock tower plugs.


    Does anyone have/know where to find a wiring diagram for the '89 RT4wd?
  • bam-bambam-bam Council Member
    Okiewagon1 wrote:
    This is very common. You picked up a 88/89 engine harness and will need to make a conversion plug to make this work or depin the square plug and repin into a round plug. You will notice that all of the colors will match up just fine. I dont remeber if the extra two wires were even needed or not I will have to check my notes.


    So this statement is basically true. The 2 extra wires are not needed if your engine does not have the FICV.

    You could also depin the car-side plug and put the '88 square one on... :?
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