Black Light Gauge wire with yellow tracer and SPADE connector??

[chaps70rt]

I am in the throws of re-installing all accessories in my 70 Challenger.   I have what I believe to be a 72-74 rallye dash wiring harness.  My records are a Service book and a coloured schematic to try and sort out what goes where.   

Problem is that I have a LGN (Light Green) wire with a round male push in connector and a separate BLK (black) wire with a grey push in flat spade connector up behind the FOTA gauges that comes out of the A/C and heater wiring harness and leads to the fuse and main harness on the firewall.  Am I missing a piece to the A/C wiring harness?  Is this something that can be ignored or is it a connection point for something important??    Can anyone point me in the right direction or advise?

Thanks ..... CHAPS

[72rtchallenger]

,,,,have you looked here at wiring diagrams
http://www.mymopar.com/72to76_wiring.htm

[06Daytona]

Is it maybe for the lighter? I know some have a spade for ground and a push on for a screw type contact in the center.

[72rtchallenger]

there are LGN colored wires that run to the a/c an heater switch low speed I believe and runs also to the resistor from that switch,also there is a LGN that is for left side turn signal,,but since you mentioned a/c an heater wiring I would check the resistor that mounts on top the heater box,at least I think its there,,and see if it is hooked up

[chaps70rt]

Well ..... I combed through the Service Manual again last night.   In the A/C section, there are more detailed schematics.    I found the same one that I have.   It turns out that the LGN plugs into the yellow triple connector with the two tan wires off the main harness.   The other black with white tracer goes to a BLK connector on the main harness in the middle of the main harness behind the tach.   Definitely a bit odd considering there was no colour match.

Thanks for chiming in.    CHAPS .....

[chaps70rt]

Correction .... the black with yellow tracer does not go to the black on the main harness .... uggh.   Thought I had it figured out.   I checked the headlight and dimmer for connectivity, but no go .......     Now I have to search through the entire harness to figure out if it is a ground or something hot?   IT is near the fusepanel ...... with a flat spade connector.  My suspicion is that it is for a ground  ...... and needs to be connected to the bulkhead somewhere .....

Thoughts??

CHAPS

[Chryco Psycho]

Thinking .......
 the only black yellow trace wire I can think of is the negative coil to the ECU

[FY1Cuda]

Does the spade connector have a little plastic shroud around it, or is it bare?  I'm thinking that if it's bare, it could have slipped out of a multi-wire connector.  For example, the wiring diagram shows  B/Y* wires going into multi-wire connectors for the headlight warning buzzer and the panel dimmer. Just a thought.

[chaps70rt]

CP ... it is coming off the dash harness near the fuse panel.   Can't seem to find out where it leads to .... or if it is on a splice and has a different colour elsewhere.  Frustrating ....    Perhaps I need to get everything working and turned on to see what is not working.    My suspicion is that it is a ground wire??

No, there is not a rubber covering on the spade connector, just bare.   Already checked for the headlights.  No continuity there, so that's not it.   The coloured schematic I have points to a horn ground.    Going to check that next.

Thanks guys for your feedback ...... Still searching ....CHAPS

[72rtchallenger]

I looked at a couple of my wiring diagrams and they show a blk  w yellow tracer that runs to the panel dimmer switch

[chaps70rt]

True enough .... found that one and yes, you are correct ..... but it is a heavier gauge wire.   Plus, I checked for continuity and it isn't that one.   Now wondering if it could be the ground for the horn, but that would suggest that the plug in for the steering column would show this at the large connector.   Didn't see that on first inspection.

[FY1Cuda]

I was just poking around the fuse box (on a 70 Challenger) and saw a thin black wire w/ a WHITE tracer so I followed it.  It went to the back of the fuse block and was a female plug for one of the three horn relay connections.  Maybe this helps.  If it doesn't, is the spade connector you're trying to find a home for a male or female connector?

[chaps70rt]

That makes sense to me.   Mine has a bare female connector on it and could definitely be for the horn relay.   Last time everything was connected my horn wasn't working .... hmm.    THIS COULD BE IT.    So, the other end is somewhere up inside the steering column then??   I went through all the connectors on the dash and could not get connectivity.  I was about to start checking all he connectors on the passenger side and got side tracked.

If it was for the panel dimmer, I would get a connectivity; test positive.   I am not getting this, so the horn could be it.   How can I test for this and where in the fuse panel is it connected?   Is it a ground??   The schematic seems to suggest this.....  thanks for chiming in.   I will check for logical placement along with the schematic in the Service Manual in the interirm.

CHEERS .... GARY!   

[FY1Cuda]

The wire comes out of the main harness (with the 100 other wires) and goes down the back of the fuse block with the ten or so others.  It plugs into the top corner spot and provides the plug-in ground for the horn relay.  It's the relay connection that is the one by itself (where the other two horn relay connections are close together).  Bend the little prong on the top of the spade up a little so when you slide it into the plastic socket, it catches and stays there.  Good luck.

[chaps70rt]

Awesome information.   I will definitely check into this on the weekend.   Never have time during the week to climb into the car stuff with operating my own business.  This is terrific news and if correct will allow me to get over the wiring troubles I have been slowly eliminating.   Then on to re-installing the interior and getting the car running again ..... it's been months.

Thanks again FY1Cuda ..... there are so many helpful people on this site.  Not sure how I could have got this far without the various people that offer their time.   Hopefully I will be able to offer some advise myself to others that have just started with their resto. 

Cheers .... Gary