Random wiring questions

[WPS 73 Bronco]

On my 73 Bronco LS engine swap I've installed the VA Gen 5, Holley Terminator X ECM, and Dakota Digital gauges. I've gotten most of the wiring complete, but I have a few remaining questions.

Here's the first one. This is the Ford wiring that terminates at the firewall, below where the throttle linkage was. What are these wires and do I need them anymore? I can't remember what plugged into them.

 

[WPS 73 Bronco]

Here's number two. Dash wiring. I've got a black w/green stripe. On my wiring diagram it shows up in two spots In pic where shown

 

[WPS 73 Bronco]

Number three, brown under dash wire.

 

[WPS 73 Bronco]

4th one. Purple wire. I can't find it on my diagram at all.

 

[73azbronco]

First off, those wires look way to good...

 

[DirtDonk]

On my 73 Bronco LS engine swap I've installed the VA Gen 5, Holley Terminator X ECM, and Dakota Digital gauges. I've gotten most of the wiring complete, but I have a few remaining questions.

Here's the first one. This is the Ford wiring that terminates at the firewall, below where the throttle linkage was. What are these wires and do I need them anymore? I can't remember what plugged into them.

View attachment 924759

Are you talking about just the red connector? That one is power to the ignition coil, and the two sending units. One for oil pressure one for water temperature. The fat pink/brown wire is the resistor wire and it’s probably molded in with the brown wire that comes from the starter relay.

 

[DirtDonk]

Here's number two. Dash wiring. I've got a black w/green stripe. On my wiring diagram it shows up in two spots In pic where shown View attachment 924761 View attachment 924760

Black with green is accessory power. And that particular connector in your hand is attached to the center stud on the back of the ignition switch.
It literally powers everything in vehicle that is switched by the key. Other than the original ignition and voltage regulator and starter.
Everything in the ACC position.
From items in the fuse box, to the gauges.
The gauge connector is completely different and it is a small splice off of the main branch and goes to the back of the instrument cluster. That one is a push on connector.

 

[DirtDonk]

4th one. Purple wire. I can't find it on my diagram at all. View attachment 924766

Probably the prove out for the brake warning lamp.
Pushes onto a small blade connector on the side of the ignition switch. Grounds to the dash when the ignition switches in the START position only.
Tests the bulb every time you start the truck.

 

[WPS 73 Bronco]

Are you talking about just the red connector? That one is power to the ignition coil, and the two sending units. One for oil pressure one for water temperature. The fat pink/brown wire is the resistor wire and it’s probably molded in with the brown wire that comes from the starter relay.

I’m questioning all of those wires coming into the engine bay in that pic. II’m thinking I don’t need any of them????

 

[DirtDonk]

Well just look at the colors. Since you're replacing the sensors and the ignition (presumably) you are probably right that you don't need the red connector wires.
The single with the Blue wire, is probably for the old throttle control solenoid (anti-dieseling) thingy. Probably don't need that either, unless you'd like a convenient spot to take 12v from for some other accessory.
If the ones in the other connector are anything resembling Red w/blue, and perhaps Red w/black (or is it black w/red?), then you only need them if you want to retain your neutral safety switch and backup lamp functions.
Working with an auto, or manual trans? Got another source for your backup lamp switch wiring? If you're keeping your main harness stock (or at least stock-ish) then I'd say you need that one.
I'm just not sure, even now that I'm looking at them on the bigger screen. But you can tell from right there what color they are, and what the other end connects to.
If you're not sure, then take a neutral-safety switch connector (assuming you have an auto that is) and see if it plugs in. If you have a manual, then there would normally be a jumper wire connecting the two Red w/blue stripe wires together, as a bypass.

Paul

 

[WPS 73 Bronco]

I still am looking for thoughts on this under dash connection.

 

[DirtDonk]

Solid brown? Push on connector and solid brown, should be pretty easy to track down. Don’t have my Diagrams in front of me, though, and can’t remember what the brown wire is for. Someone will have that info I’m sure. Maybe Oldtimer has a handy diagram.

 

[DirtDonk]

Heater blower motor perhaps? Whereabouts is it located? I know from the heat switch to the resistor is an orange wire and a red wire, and I forget what color it is out to the motor. But perhaps that is the heater power to the switch itself.
Is there a push on terminal in the center of the heater fan switch?

 

[Oldtimer]

Paul's got it.

It is hidden in top right corner of schematic you are using.

 

[WPS 73 Bronco]

Are you talking about just the red connector? That one is power to the ignition coil, and the two sending units. One for oil pressure one for water temperature. The fat pink/brown wire is the resistor wire and it’s probably molded in with the brown wire that comes from the starter relay.

Guys, back to this thread. I’ve figured out everything based on all of the help, with the exception of the first pic. In my build I have a Holley Terminator X running my LS3. As Paul noted in his first response as to what those wires are for, I think I can eliminate that entire wiring bundle.

Am I correct?

 

[DirtDonk]

If you’re gonna completely rewire the instrument cluster, completely rewire the back up lamps, completely rewire a neutral safety switch (in case you’re running an automatic transmission), and don’t want an extra accessory power wire that you could use for something, then yes, you can eliminate that wiring bundle.