Alternator wiring, found a problem

Soooo, hooking up my Edelbrock electric choke to the STA post I discovered several issues. When I went to unplug the harness that attaches the Autolite alt. to the starter solenoid, I noticed that there were only three wires running into the harness where there is 4 terminals as you can see in the photo the right one is missing. The wire I’m holding is just chilling on a deserted beach. What is this wire?

20170612_174026 by Dave Hamilton, on Flickr

So I walk up a little further and the harness connected to the box is loose and I have another random chilling deserted beach-goer wire. I don’t know what any of this is supposed to go to. I know I’m going to have to order a new harness, but WTF? Figured I’d order the box below the starter solenoid too. I need some guidance before I buy.

20170612_174540 by Dave Hamilton, on Flickr

Uhhhh, does that wire loom really connect from the front starter solenoid all the way through the core support, to headlights and horns the the firewall behind the brake booster? Someone tell me there’s a very simple connection right by the alternator so I don’t lose my mind…its the front electrical harness isn’t it…

Ok, edit here, so after looking online, I can so far only find an XR7 Under Hood Wiring Harness for $392. I think I might consider cleaning this one up a bit, but most of the connectors inbetween the core support and grill are corroded as hell and I’m not too great at electrical and don’t know where to start on getting them. Maybe a pigtail? I know the PO spray bombed the engine compartment so if I peel back the wrapping I can see the colors of the wires.

That big black wire in your hand? That’s the charging wire where all the current from the alternator comes from. Without it the system draws its current from the battery. Yes, you could easily pigtail that wire assuming the correct gauge and method… I would have thought there is a repair kit for that connector by now… anyone?

Ok, that’s a start. Where does it connect to? What gauge?

That big fat wire and the four pin connector needs to mate with an alternator harness. The second picture showing a naked beach-comber is for a radio noise suppression condenser or an optional plug for RUN-only power (depending upon it being yellow or green/red wire, respectively).

What year is your car? I may have a Cougar headlight harness that I can refurbish for $75 if you send yours in as a core or $100 if no core.

69 standard 351w fix non ac. I was going to look at some shops around me who I know do auto sound electrical, but your here, you know Cougars?

I work on Cougars, yes, but not as much as the Mustangs. That plug is hard to find, as it is used on tach-dash Mustangs and tach headlight harnesses are in high demand. As luck would have it, all of my Cougar headlight harnesses have the three, not four pin alternator connector. Sorry…

I have the complete harness, the main underhood harness plus the harness that connects to the alternator. I just removed the Alt. Midlife, where does that big fat wire go to on the Alternator harness, does it plug into the fourth pin? Could you tell me where the radio noise suppression goes as well? I’ll try to look through my manuals as well, but sometimes a nice description can be easier than more vague manuals :slight_smile:

Just spend a half hour with Lift Off and citrus degreaser on the wires to remove black spray paint and grime, I can start to see the wire colors which helps bigtime. The charging wire does go into the fourth pin I see based on size of opening and alternator harness. What is the best method to reconnect the charging wire into the pigtail? The rubber cover of the harness doesn’t come apart, so I’m thinking cut back the charging wire, reveal fresh metal, stick it in the pigtail and tape it? Secondly, is there a pigtail I can buy to redo the four pigtail connection on the harness? Thirdly, why does my 69 Standard harness have four connections here and most examples I see including reproduction XR7 harnesses only have three?

Now the radio noise suppressant wire is sheared of at the but connector i guess it is and using WCCC ( I can see it is the yellow wire with black butt connector near bottom right. Do I need this?

Want you guys to know I appreciate your help. Electrical isn’t my strong suit, but can figure things out and make connections.

If no connector is available, I would remove the wire from both connectors and solder a single post connector to each end. Sticking a stripped wire into the original connector will not fix the problem.

Because the XR7 has an ammeter instead of a light.

You really should get a 69 wiring diagram: 1969 Mercury Cougar Wiring Diagram – ClassicCarWiring

Thanks Bob, I’ll definitely use it. I think my frustration with how many issues I’ve had from the P.O. has made me a little manic. I need to inspect all connections on this harness then order from WCCC. Rich over there can set me up with any connector I need.

TheRktmn is 100% correct. What I would do is cut back the wire a bit to expose good copper and then solder it to its mate on the alternator harness after it has been cut off of it’s plug. Once a wire pulls out of a molded connector, no amount of effort will be good enough to get it back in and have it reliable and effective.

I wish someone would reproduce the headlight side of that 4 pin plug. I cannot keep them in stock due to the high demand. Unfortunately, they are pretty much unique to the 69 Mustang/Cougars.

Ended up getting in contact with Rich (Mistress) at WCCC who set me up with the portion of the harness that sits in the engine bay. Cut my original and soldered the multiple wires back together, heat shrunk and lots of duct tape. All connections were remade and looks factory. Yet another little gremlin has been microwaved.

Duct tape? Should be harness wrap (which looks like electrical tape but has no adhesive).

Don’t know much about electric so I’ll man up and ask in seriousness what the difference is and does it really matter?

Duct tape is typically gray, has a fibrous base, and typically 3" in width. It has very strong adhesive on one side. Harness or black electrical tape is typically vinyl and 1/2 to 3/4" in width. Scotch 33+ is what’s found in most electrical hardware sections of stores and supply houses.

Wire Harness Wrap Pg 176

Well, I feel like I’m in second grade again. I misspoke I used electrical tape. That should be fine yes? I figure with the soldered connections and shrink tubing, I want something that will help keep everything in place so as not to have one of them come loose from vibration, a tug, anything at all.

The electrical tape when it gets hot will ooze out the adhesive out. It will turn the wires tacky and eventually fall off. I know, I did it once.