1979 F-150 4x4 with a 460/C6. No air conditioning.

I have installed the EZ Wiring 21 circuit harness. I now realize that a smaller number of circuits would have worked, but 20/20 hindsight being what it is…

I have gotten most of the wiring done, but like any other project, I have parts “left over” that I’m not too sure about. I have searched high and low, here and on the net, but some questions are left unanswered. I’ll try and break it down by area.

Wiper plug-

I have three leads that do not match any schematic I can find. One should be power in, one power to the pump, and one shows going to the ignition switch. The book shows two white/black leads, which makes it even more confusing.

Green/Black = ?
White/Black = ?
Orange/White = Ignition switch - but not sure how to (or if I need to) wire it in.

Instrument panel plug-

I have an idiot light dash, no gauges. I was able to drop the leads for the coolant temp and oil pressure switch as I’m running a gauge cluster. Most connections were pretty straightforward. But I have some left over tails off of the plug that don’t match anything.

#1 - Black = ground (obvious, but…)
#4 – Brown (or tan) =?
#6 – Black w/ a resistance wire = ? Another ground?
#7 – Pink = ?
#11 – Purple/White = Brake switch sensor. Do I simply run this to the switch, and then the other goes back to the starter switch pigtail?

Headlights-

P – Yellow = ? Book shows this going to the horn relay… Not really sure how that works. Research also shows it going to the parking lights. I have two brown leads (R) that have wired one to the front parking lights and the other to the rear parking lights. It’s also a heavier gauge wire.

I - Brown = ? Does this simply tie into #4 from above?

Dash key switch –

This has been my most troubling, but I think I have it. I just want some confirmation before I start connecting things permanently.

Starting at the top of the pigtail and working clockwise:
Purple/White = Brake switch sensor. Same question as above.
Red/Green with second red resistance wire at the plug. Within 6” it changes to Red/Yellow (split to one heavy and one light gauge) = IGN SW IGN. Do I need to keep the light gauge, or can I cut this off completely?
Red/Blue x2 = NSS – I assume this is a looped switch? Book shows this as Blue/Red.
Orange = IGN Switch ACC
Black/Green IGN Switch START
White = ? I have no ideas on this. I can’t find any reference to it at all.
Yellow x2 (center) = IGN Switch POWER. New harness has this split, so I’m assuming one to each?

Finally, the harness itself –
I have the following wires that I’m not exactly sure what to do with. They are all tied into the fuse box and appear to be a part of the dash-wiring group.

Light Green – Left Backup
Light Green – Backup power
Orange – Brake switch power
White – Brake switch

You guys have been a wealth of info on all things dentside! Thanks for the help!

 

Hey man, I will get you some pictures and stuff from my EZ harness that I just finished and post them. Your wipers only need the one power wire from the harness to work if you have non intermittent wipers at least.

 

Conversion table for the TSS and proper wiring for the IGN switch.

 

I think the wiper power one is blue on the harness side, and the power wire is orange on the truck side.

 

Problem I'm running in to is that the existing pigtails have some different color leads, or leads that don't exist in the reference material. Heck, I've even downloaded Painless and several other manuals to see if there was any reference.

And did you omit the pigtail on the key switch?

 

I had that problem too. The way I wired up my tail lights was exactly opposite of the color coding, but the headlights were pretty much exactly right. It is best to use ford diagrams rather than look at colors for most of it. It is a good thing the wires have labels on them! I omitted the pigtail for now with the switch, I will reinstall it later.

 

So, I may have answered one of my questions by accident... JBG has a nice pic of the NSS and lo and behold, red/blue wires and what appears to be a white wire.

 

Dewd- Did you get the colors correct on your switch?

If I'm looking at your wiring correctly, it appears to be the following:

Position = EZ harness = Original Color

I1= Ign Sw St = White wire

I2 = Ign Sw Ign = Red/Green (aka split to Red/Yellow)

ACC1 = Ign Sw Acc = Black/Green

ACC2 = Ign Sw Coil = Orange

Batt = Battery = Red

Batt = Battery = Black

Purple/White go to low brake switch

Red/Blue got to NSS

The original orange goes to the heater fuse (ACC2). New harness has it's own power lead for the heater. I have an HEI, so was sure that was the correct position.

 

The configuration for the switch I pictured above is correct as far as I can tell. Works for me. My truck is a manual so no NSS for me. Don't forget your ballast resistor!

 

This is what I have come up with for mine. Mine's an auto, but I think for the ease of things, I'm going to defeat the NSS. Nothing is stock on it as it is...

Circuit = Position = Original Color = EZ Color/Label
C21- BATT = Yellow = Red/Power
C21- BATT = Yellow = Black/Power
C297- ACC1 = Black/Green = Orange/IGN Switch ACC
C101- ACC2 = Orange/Delete (Originally to Heater Only Fuse)
C32- ST = Red/Blue X2 (delete one) = IGN Switch Start (goes to start relay “I”)
C977- P1 = Purple/White = Low Brake Light (Tied to New Purple Splice)
XXX- P2 = no wire to this terminal
C732- I1 = White = Pink/Coil
C16- I2 = Red/Green = Brown/IGN Switch IGN

The original white wire and the orange wire both should be powered when the truck is running. My orange was tapped into poorly by the PO(S) and I'd rather not chance an issue in the future. The white went to the ignition module (not used with the HEI) and then to the original coil.

If anyone has any thoughts on this configuration, holler up.

And where did you put your resistor in at?

 

Sounds like you have different colors than I do for some reason, but looking at it, it looks correct. I just split the wire for IGN IGN and spliced in the ballast resistor.