My truck is a 1978 F100 with a 302. I have a bunch of wires that I have no idea where they connect to, so here goes.

1. These three wires come off the regulator. I'm thinking they connect to the alternator, but I'm not sure where. One orange, one black, and one white w/ black stripe.



2. These four also come off the regulator. At the top of the pic, there is a short yellow one. The three at the bottom are black, red w/ a white stripe, and red w/ a black stripe.



3. The wire on the right of the pic, coming off the horn. Looks like it might have been cut.



4. This section was just laying on the fender, near the windshield washer fluid. One wire is blue and one is yellow w/ a black stripe.



5. I'm not sure what this is, but the black, C-shaped plastic piece says TACH TEST.



6. This isn't related to wiring, but does anyone know what this is?



There are a few more, but I think this is enough for now. I'm also not 100% sure that the wire colors are right. They're really dirty and faded, so it's hard to tell. I can get better pics once I have time to clean the wires off and figure out what color thay really are.

Thanks for any help,
Rebecca

 

1) These wires do go to your alternator. I'll try to find an illustration to better explain later.

2)These three should go to your starter solenoid which would bolt to the inner fender between the voltage regulator and battery.

3)Not exactly certain, will it reach the voltage regulator? Looks like the same color wire as the one thst disconnected on the voltage regulator.

4) Don't know. Mine does'nt have a hole on the inner fender like that. Just for giggles, check to see if they go to the front side marker light.

5) This is the connector for the ignition coil

6)Evap cannister. It should have a number of vacuum hoses connected to the top of it. It basically stores gas vapors from the gas tank and carburetor until the engine is started at which point they are drawn into the engine and burned.

 

3) Looks like the PO may have had dual horns at some point in time.

4) Not sure what that is for either, it isn't factory. Where do the wires go from there?

Josh

 

a little fantastic or 409 and some paper towel
would clean the wires like new.

 

The truck isn't a trailer special by any chance is it?

If it is, There is a match for #4 in the wiring diagrams.

 

Here's some more info for picture 1 (alternator wires)

Back view of alternator
http://www.fordfuelinjection.com/pub...ternator02.jpg
If you'll notice in the picture, there are only three terminals which have a plastic ring around the stud. These are the ones you need to hook up to the wires in your picture. Nothing goes on the other two.

Wiring diagram of 1G alternator
http://www.fordfuelinjection.com/pub...ALT_wiring.gif
The three terminals on the back of the alternator with the plastic rings should be marked as battery, stator and field.
The "B+" or "Batt" (for battery) terminal is where the orange wire would go.

The white and black wire would go to the terminal marked "sta" or stator.

The black wire would go to the field terminal.

More info for pic 2
The two small wires with litte boots go to the starter solenoid which I see is missing from the inner fender. Here's a picture of one.
http://i14.tinypic.com/7ysavmf.jpg
It would attach to the inner fender by the two metal ears at the top. Notice the two large copper studs sticking out of each side, the positive battery cable and the wire with the ring terminal in your picture 2 would go on the stud on the left. The large cable that goes to the starter would go to the copper stud on the right.
Now notice the two small studs sticking out of the front at the bottom. The small red wire with the little boot would go to the small terminal on the left marked "s". The other small brown wire with the little boot would go to the small terminal marked "I".

 

Thanks for the help guys!

Bullitt390 - The wires from pic 4 don't connect to anything on either end. There is a plug in connection on one end. I can get some more pics later.

81-F-150-Explorer - How would I tell if the truck is a Trailer Special? I don't think that it is b/c the badges just say Custom.

Looks like I have a lot of work to do!

 

The horn wire was tapped for something else. Maybe for an air horn. Looks like the tapped wire is brown which is the parking lights wire.

It also looks like the truck is missing a starter relay.

 

This is incorrect.

Black/Orange wire hooks to Battery. Or "Batt" or B terminal. The other end of this hooks to the starter solenoid's Battery lug. This in turn hooks to the Battery + side with the red battery cable.

Orange/Lt. Blue wire hooks to the field terminal. This goes to the voltage regulator's F terminal. "Field".

The white wire hooks to the stator terminal as mentioned above. Goes to the Electric choke, and the S terminal of the Voltage regulator on "Warning lamp equipped" vehicles ONLY. The Green/Red stripe wire hooks to the "I" terminal on warning lamp equipped vehicles ONLY.
On Ammeter equipped vehicles, The white/Black wire goes to the electric choke ONLY. The wire that goes to the stator terminal on the regulator is replaced with the Green/red stripe wire, and the I terminal is left unused.


Source of Info: Ford 1978 Wiring Diagrams.

 

The Trimline Custom, Ranger, Ranger XLT, or Ranger Lariat, doesn't determine if the truck is a Trailer Special or not.

The easiest way to tell is to look at the tailgate, and towards the bottom, below the O and R there is a badge that is in the shape of the Lower 48 states. This badge is the Trailer Special badge. This is not conclusive if it's missing, because tailgates get swapped or badges go missing.

The wires and colors for Picture #4 resembles a portion of the optional trailer wiring. Not confirmed however, because the wires are out of place.