Identify This Plug

[lazabby]

I think this is one of those plugs that's unused. It's part of one of the wiring harnesses running along the back of the engine. Is this used for anything?5148951490

[Lwanmtr]

Im curious too, as I have that plug...and cant find where to plug it

[sdg3205]

Probably for the auto.

[Lwanmtr]

Unless I pulled off somehow (which I admit is a possibilty) I cant find where it plugs in..and I have an auto-trans

[AugustneverEnds]

I have an auto too and that plug is unused on mine. Guess it was for something that never made it to production.

[Bitsyncmaster]

What are the wire colors?

[Lwanmtr]

Green-Red and Green White

[Bitsyncmaster]

Green-Red and Green White

Do you have reverse lights? That connector is green/brown and light green/white but many times I have found schematic wire colors are not always correct.

[Lwanmtr]

I cant check for reverse lights...battery is toasted and the dash n stuff are all disassembled..hehe

[AugustneverEnds]

Hold the presses!!! I think you are right (as usual) Bitsyncmaster, those wire colors correspond with the reverse lights: http://dmctalk.org/showthread.php?40-All-Wiring-Schematics

I don't have my car handy to check right this second but I can't remember if my reverse lights work and the guy I take it to for NY's yearly inspection usually limits his inspection to brake, tail, head lights, high beams, turn signals and a working horn so the reverse lights have been neglected.

[sdg3205]

My brake lights work and that plug still hangs loose in my engine bay.

[Lwanmtr]

My brake lights work and that plug still hangs loose in my engine bay.

What about backup lights?

[sdg3205]

Sorry I totally meant reverse lights. Sorry!

[Lwanmtr]

Yaay a mystery plug...well a thoery...the cars were made in Ireland...maybe that plug was for the leprechaun catching accessory?

[Ryan S.]

I thought someone told me that it was for diagnostic port. I could be wrong.

[Bitsyncmaster]

My brake lights work and that plug still hangs loose in my engine bay.

There is a two pin connector with one orange wire and one purple wire which does connect to the diagnostic plug.

[Ron]

^ +1, Dave ^


Hold the presses!!! I think you are right (as usual) Bitsyncmaster, those wire colors correspond with the reverse lights:

The reverse lights are G/N (Green/Brown).

G/R (Green/Red) and G/W (Green/White) are for the directional signals.
Shannon, what colors are yours?

[sdg3205]

Yaay a mystery plug...well a thoery...the cars were made in Ireland...maybe that plug was for the leprechaun catching accessory?

It is for plugging in the potatoes.

[Jimmyvonviggle]

I'm pretty sure Dave S identified this in another thread. Cannot remember the thread or what he wrote, but I'm sure he will chime in soon.

[Lwanmtr]

It is for plugging in the potatoes.

I just checked and it seems the potato mounting bracket is NLA

[sdg3205]

I just checked and it seems the potato mounting bracket is NLA


I have one I'll sell you. I'll even include a gallon of torsion bar fluid.

[Lwanmtr]

I have one I'll sell you. I'll even include a gallon of torsion bar fluid.

No thanks, I stocked up when I bought my car, but I'm sure someone may need it.

[lazabby]

What are the wire colors?

There are two light blue/black wires going into one hole and one black wire into the other.

[DMC5180]

There are two light blue/black wires going into one hole and one black wire into the other.

The only circuit with a LT. BLUE/black tracer is the Cold Start circuit.

I don't recall a two way connector of that type in the engine harness for the cold start circuit.

Are you sure it's not BLACK/Lt. blue tracer?

Perhaps a better photo would help.

Also, if you have a DVM, do some basic continuity test between the connector and the other end in the Bulkhead connection. If you locate the bulkhead connector and pin location we tell you the circuit it belongs too.


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[lazabby]

Looks like black with light blue stripe.51575

[DMC5180]

Black with blue trace is vacuum advance circuit. It may be unused. Since the doubled wires creates a continued circuit to other terminations. The schematic shows a junction connection where the other side is a capacitor/ noise filter to ground. It may have not made it into production. I don't recall seeing one in that location and if the plug looks like it was never connected to anything, I wouldn't worry about it.


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[DMC5180]

Shannon

I think you've help me solve own mystery plug.

I have what you might be missing. The funny part is that I don't your plug in my harness. Not on my original late 81 harness or the late model (82 - 83) style I currently have installed.

This is the missing piece of your puzzle.

https://uploads.tapatalk-cdn.com/20170519/d85ca8fe1c8e1ff33b6e74bd9fd54424.jpg

The white connector goes to the black cylinder in the back ground. It is integrated into the harness that goes to the ignition resistor.

https://uploads.tapatalk-cdn.com/20170519/3894ba2387017ea43a169a3eab7a1613.png

BU is Black blue the made a mistake with the Red dots on the blue wire.



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[Bitsyncmaster]

That capacitor for the vacuum solenoid is mounted on the intake manifold on some cars. On my car they put it on the back side of a bulkhead connector but attached to to the wrong side of the solenoid wire (the power side).

What it does is clamp some the inductive spike when the idle switch opens and current stops in the solenoid. I found without that cap that would cause my RPM relay to prime if you stepped on the gas (engine not running). It may also cause a miss fire when you step on the gas from idle (my guess as to why it was used). I put the cap in my idle ECUs.

[DMC5180]

I've seen pictures of the one tapped into wiring by the idle micro-switch. I don't have one.

I also don't have the plug connector that Shannon has.

I only have the unconnected Cap, unless I have one on the backside of the BH connector like you. But since I have your ECU I guess that doesn't matter [emoji6]


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[Bitsyncmaster]

I've seen pictures of the one tapped into wiring by the idle micro-switch. I don't have one.

I also don't have the plug connector that Shannon has.

I only have the unconnected Cap, unless I have one on the backside of the BH connector like you. But since I have your ECU I guess that doesn't matter [emoji6]


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Yes it does not matter since my ECU puts it on the circuit. I wonder if all the caps at the bulk head connector were wired wrong or just mine.

[DMC5180]

Yes it does not matter since my ECU puts it on the circuit. I wonder if all the caps at the bulk head connector were wired wrong or just mine.

The best part of this thread is that I've finally been able to answer the mystery of what my own mystery connector/capacitor was intended for.

I asked Stephen Wynne about my connector and he just said it was an unused rolling production change.

Clearly, based on the Early 81 schematic, My Cap was intended to be connected to the VA circuit wiring, but for whatever reason they deleted the connector in the engine harness. Perhaps it was a manufacturing error, since the cars with the capacitor near the micro-switch look to have been installed as an afterthought using red scotch-locks. Looks like something done in the QAC's.


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