What wiring am I missing here?

[fuentesfranko]

I'm putting together everything back in my engine bay after doing a lot of mechanical work. I can't figure out 2 things.

1st picture, what this connector is for! it's coming out of the firewall. I already have connected the connector that goes to the temp sensor, oil sensor, coil, and I don't seem to have any other harnesses.

2nd picture, where does this yellow female connector goes? it's attached to that silver ....capacitor? not sure what that is, but I know that silver item gets screwed on to the body near the alternator. Just can't figure what to do with that yellow female connector. (I've already connected the horn relay, no it shouldn't be that.)

 

[DirtDonk]

What color are the wires going to the connector in the first picture?

And the second picture that looks like the noise suppression capacitor for the ignition coil. Connects to the positive side.
Based on the connector looks like it might go into the horseshoe connector on a 74 and later.
What year is yours?

 

[Broncobowsher]

I think that second picture is a noise suppressor for the voltage regulator. Given the location and there is usually one on the old mechanical voltage regulators.

But I am no expert on the original wiring. I know functions, not color codes.

 

[DirtDonk]

If it's Yellow wire it's for the voltage regulator. You can verify that easily by measuring voltage on it. Once the battery is connected you will have full 12v on that Yellow wire all the time.
And since it's disconnected you won't have a working alternator either. If you've run the engine yet and found that it's not charging the battery, that's why.

It goes into the third position on the regulator's 4-position connector. Might be marked with an "A" for armature. Or for "always" as I like to think of it.
Which wires are in your regulator connector at this point? Or did you swap out for an internally regulated alternator and get rid of the old fender/firewall mounted regulator?
If the other end of that Yellow wire goes off into the harness somewhere, that's just another confirmation. The horn relay has a Yellow wire connected to the starter relay as you mentioned. This one is probably connected to the big Black wire via a splice down in the harness.

Paul

 

[fuentesfranko]

@DirtDonk correct, it goes on the regulator! Somehow it fell off, I think the tab that holds it broke. I do have the fender mounted regulator.
So in the first picture, the colors are yellow and red. Am I missing a harness? if so, what would that harness be called?
I don't seem to have anything that goes into that connector.
EDIT: It's a 1976 Bronco Automatic by the way.

 

[DirtDonk]

If somebody doesn’t come up with it before me, I’ll dig into the wiring diagrams and see what those colors coincide with.
But it’s not unheard of to have blank plugs under the dash or in the engine compartment in most vehicles it after the 60s and early 70s.
They would typically use the same main wiring harness for all vehicles whether they had a particular option or not. And for 76 it could be a smog control item that either wasn’t there in a non-California vehicle, or it was removed by somebody.

 

[Steve83]

Study this page & the NEXT few:

(click this text)

 

[fuentesfranko]

Thanks Steve! I found some info on it but not much. "Circuit 640 - R/Y hash: Power from Fuse 18 to brake warning light & tach"
Not sure exactly what that means and why I'd be missing that plug/harness. Might be what @DirtDonk said where the plug was originally blank

 

[Steve83]

There is no connector on that circuit - read the locations at each end of it; it's inside the dash. Look at how connectors are shown on the rest of the pages.

 

[904Bronco]

Given how much dirt is inside the two prong connector, I am going to say that it wasn't plugged into anything. But, it would be nice to know what it supposed to be for just the same, even if as Paul says, a plug for an accessory yours doesn't have.

 

[DirtDonk]

If the colors are actually a faded Red w/yellow and an old tired worn out Blue color, they might be for non-existent Throttle Control Emissions Solenoid (Blue) and a Distributor Control Modulator (Red w/yellow) which was part of an ambient system.

Any idea where your Bronco was originally sold? If built to FED spec those items might not have been included from the factory.
If sold in CA or CO or other emissions state, they were likely some of the first things removed from the engine when the first couple of owners decided they didn't need, or want any of that dreaded "smog crap" under the hood.

The factory style diagrams in the aftermarket manuals (Hayne's in this case) do not show connectors, but since both of those control thingies would have been on the top of the engine it would make sense for them to have shared a connector.

Paul