1971 ford f100 head lights blink on and off how do I fix it

http://ibb.co/dXA7Bn

Found this for 5.0L engine.
Don't know if that is what you needed?
My wiring diagrams for that model year, isn't very good.

Each carb kit comes with compete instructions on repair.

There is a flasher unit for the turn signals, separate from the hazard flasher, that is under the dash. If the fuse for the turns is good, and you already know the bulbs are good since the hazards work, then you may have a bad turn signal switch.
When you use the turn switch, do the bulbs come on and stay on, or nothing? If they come on and don't blink, then it's probably a bad turn flasher unit. If they don't come on at all, suspect a bad turn signal switch. But first check the fuses, then pull off the connector to the turn switch and see if you have one hot wire there, with key on. That one hot wire will be from the fuse.

It sounds like an ignition module failure or the ignition coil is overheating. If it is fuel injected, a fuel pump relay could be the problem

Hello! The Turn/Hazard Switch is defective...Replace switch...Let's check the vehicle grounding just to be sure...If you have a multimeter set in on the lowest ohm scale...Place one probe on the center of the negative battery post...The other probe to bare metal chassis...Record reading...Move probe from bare metal chassis to the engine block...
record reading...Send results...Guru.............Saailer

I’m happy to help further over the phone at https://www.6ya.com/expert/david_6df67de3b14de867

use 10W40W

Ford Neutral Safety Switch; Ford Reverse Light Switch; Backup Light Switch.

The Neutral Safety Switch wires in my 1971 Ford F100 are orange with a blue stripe.
The Reverse, or Backup Light Switch wires are black with a red stripe.

There are two sets of two wires across this combined neutral safety and backup light switch, for a total of 4 wires. Photos are at the end of this post.

The switch for the 1971 Ford F100 pickup truck is the same as in many other years and models. For details, including parts numbers, see the following quote from an expert at Ford Truck Enthusiasts:
http://www.ford-trucks.com/forums/287185-back-up-light-and-neutral-safety-switch-2.html#post5601846

The neutral switch also controls the backup lights, and is the same 1967/77.

C7TZ-7A247-A .. Neutral/Backup Switch (Motorcraft SW-600)

There is no separate backup light switch..except on 1967/68 F350's.

Neutral switch location 1967/77:

The plastic half moon shaped neutral safety switch mounts on the outside lower portion of the steering column (NOT on the transmission!).

It's activated by an inverted Y shaped lever that snaps on the shift tube

D0TZ-7B097-B .. Lever, Neutral Switch Actuator = From FTE sponsor DIRECT FORD PARTS: Ford suggested retail price: $18.72 / FTE member net: $13.23.

The switch is also still available from Ford, but the website is down so I can't post the list & net prices. .

1978 is the FIRST year the F100/350's have the neutral switch mounted on the transmission. __________________

Bill // Retired Ford Parts Manager // SoCal Chapter member // Part Number Research: 1928/2001 FoMoCo vehicles.

IMAGES

Driver side of the neutral / reverse switch showing the travel slot for the switch arm, the return tensioning spring, and the arm.


The front, steering wheel side of the neutral / reverse switch after removal from the steering column. The switch's two functions are actuated when the lever in the column moves the switch lever shown here to different positions as gears are selected.


The neutral switch is installed on the steering column near the firewall, with 5/8" bolts into the steering column (visible hole) and down column from a rectangular opening in the column housing. The actuating lever for the switch is attached to the gear shift shaft inside the housing; the lever is visibly protruding from the opening in this image.


Back of neutral / reverse switch, showing the wiring attachments. Black with red stripe is the backup light wiring, Orange with blue stripe is the neutral safety switch, it prevents starting in gears other than neutral & park.

I need a wireing diagram for f100 truck

you dont need to splice the harness ,look closely every thing will plug in you just need to take the distributor from the old motor and put it in the implant motor...if thier different motors get one from a wrecker that is the same year as the truck and put it in the implant motor