66 bronco wiring issue

[Rdtrip]

Hi all. I have a 66 bronco with new wiring harnesses from bronco graveyard. I am confused on some of the wiring. The main headlight harness that goes to the solenoid is strange, it has a small wire at the connector that plugs into the alternator harness. The alternator harness has a much larger black/yellow wire that goes from the alternator to a junction block, or not? I have no junction block,and not sure if it's needed. I can't get any spark, it cranks over fine. I also only have left side brake/tail from the new dash harness, nothing on the right side. I believe I've followed every possible direction to get this working. I have not posted a pic of what I have and I need help getting things wired correctly. I'm not sure how to post a pic.

 

[Rdtrip]

I am now a contributor after happily paying the $12..lol. So these are a couple pictures of the harnesses I have hooked up and I'm not sure if they're correct or not. Something doesn't seem correct. Thanks for the help.

 

[ba123]

Not sure I can help on this one but you should add some info for clarity.

Is it this one?
https://shop.broncograveyard.com/1966-Under-Hood-Wiring-Harness-New/productinfo/18007/

It's actually made by Dennis Carpenter. I don't see any instructions online for it.
https://www.dennis-carpenter.com/tr...qRof8LdZYAgX1u94q4LduoysNBRGPdOlCgqYjmPu73W2h

I can only find this other thread mentioning it:
https://classicbroncos.com/forums/threads/1966-best-wiring-harness-for-quot-originality.312295/

IMO, you should figure out why you don't have spark before the headlights...unless that same wire that powers the headlights also powers your coil.

Did any instructions come with the kit?

 

[Rdtrip]

Yes that's the harness I purchased. In staring intently at this harness, the alternator harness I purchased also from Jeff's appears to be different. I looked up what another member said about a 6 cylinder mustang alternator harness and that one appears to be correct. Here's a couple pics. I'm not sure,but I think the mustang alternator harness is what I need. Thoughts?

 

[Rdtrip]

The one pic on the floor is what Jeff's says is correct, but it doesn't jive like the mustang one does.

 

[DirtDonk]

Why is there what looks like new tape, and a new crimp-on terminal with the blue insulator, on a brand new harness? That's not how they come from the vendor, correct?
And what is that Yellow wire on the back of the alternator? Isn't there a larger gauge Black w/yellow stripe wire in there somewhere?

It won't fire now, but beyond that, it looks like it won't charge the battery either.
Got a pic of the voltage regulator wiring as well?

Good luck. We all know how frustrating wiring can be!

Paul

 

[DirtDonk]

For my comment on the wire colors, I know that '66 can be a beast of a different color in some cases. But in theory at least, your instrument cluster is still the same standard Bronco cluster with an ammeter. Correct?
The Mustang harness states it's for a vehicle with warning lights. Broncos never had warning lights and instead had full gauges.
Ford wired the two completely different from one another, but being a '66 they may have created a hybrid!

Paul

 

[Oldtimer]

66 under hood harness was a one year headache that may have more than one flavor.
JBG lists serial numbe restriction for the one they sell. "Fits Serial # 788,000 - 830,001"

Can you post a picture of main harness side of this connector, showing wire colors and which pins they line up with?

My guess is you want an alternator harness that looks like this,

and the BK/YL connector near plug on Alternator harness would connect to this wire in your harness,

using a junction block similar to this.

What color and gage is this wire, and where does it come from?

Read this thread, and the ones it links to.

1966 alternator wiring issue

Hi, I am attaching a lousy pic (the only one I have) of the existing wiring for my 66. As you can see from the picture there appear to be 2 wires (blk/yel) and (blk) going to the junction attached to the inner fender next to the starter relay. If you look closely you can also see a ground wire...

classicbroncos.com

What you will probably end up with.