I bought a 1967 f100 recently. I has a 351w and a 3spd. The wiring is a mess. The headlights dont work. The passenger side taillight and blinker doesnt work. The driveside taillight works, but the blinker doesnt work. The brake lights dont work.... well maybe the short list is the things that DO WORK. The parking passenger parking light, drivers rear hazard light. I dont know what to do or where to turn. Ive looked at every wiring diagram and nothing seems to match. I dont know where the problem lies. There isnt two blinker relays. The brake switch is different that the original one that should be there. And the ignition switch isnt the one with the post on the back. Its one that has the multiple posts on the back... one of a 69 f100. Theres wires running nowhere, and i have no idea what they are for. Theres extra wires on the ignition switch, and i have no idea whay they are for either. Needless to say, i have NO idea what to do. Ive chased every where, followed multiple wiring diagrams, and I cant figure it out. I need help... BADLY! I want to figure it out before i spend the money on a new wiring harness..

that is unless someone has a complete harness on hand that they want to sell?

Any advice is WANTED and NEEDED!!!!

 

Now don't get exasperated. You can do this. Let's start with a 67 wiring diagram. Print it out and get your colored pencils out. You will need a 12 test lamp and a multimeter with a continuity tester (audible)/ohmmeter. And get 3 pair of alligator clips and wire to make a 4 ft, 8ft, and 20 ft jumper wires for circuit identifying and continuity testing. Now start with the source which is the battery. Go to your starter relay on the fender, and then down to your starter making sure your connections are bright and tight. Then go to your alternator and start with one wire tracing it to the fuse panel. Do one wire at a time marking it on the diagram with the colored pencils. Then work outward from the fuse panel one wire and one circuit at a time. To identify a circuit using the continuity tester/ohmmeter, disconnect the battery and connect the jumper wire to the end of the circuit and run the wire back to the start of the circuit. Ohmmeters do not like powered circuits as some of them will start the Mr. Bill scream at you if you could too close to a powered circuit (Ohh, nooo). Or they just go poof and the secret smoke is released. Don't ask how I know. Touch the meter leads to the jumper wire and the start of the circuit. Hopefully there is a noise emitted, or the meter goes to 0 which means continuity or 0 ohms. Hopefully this helps. It will just take time to sort out each wire and circuit. Just remember to start at the source and work to the end of the circuit documenting on the diagrams if there is a change in the color code.

 

A test voltage meter is your best friend. And FORDification.com has all the wiring diagrams. Don't know if this helps
Orich

 

That chart may say 1970 on it but it was used on your truck too!

 

When you have multiple electrical problems...just SLOW down and only tackle one circuit at a time. Like make the headlights work and fix EVERYTHING you find on the way, leaving no marginal things like old crummy wires, or poor looking connections. You can find most electrical problems with your eye, but a meter will help you go in the right direction.


Lots of diagrams here:
Ford Truck Technical Drawings and Schematics - Section H - Wiring Diagrams


Good luck and go slow, one piece at a time.

 

This is the best information anyone has given me yet. Thank you so much for you good luck wishes... i will take your advice and go slow. Thanks people!

 

Wiring on these rigs is actually rather simple. Not like modern vehicles. Most people get scared about wiring. True, 3X going slow, but keep eyes open. And notice my sig.

 

UPDATE!!!

Greetings! Wells the puzzle as always starts with the edges, and works its way in!
Some of the issues are clearing themselves up. Turns out the dimmer switch was the cause of the non existent headlights. Figured out the brake lights, and the parking lights front and back. Now the remaining issue is such:

When i turn on the headlights; the front parking lights go out. I didnt have time tonight to try to chase down the issue. Does anyone have an idea?

Then the blinkers and the emergency blinkers....

Im not sure, but i think that the relay is bad. Im gonna go to an auto parts store tomorrow, and pickup a new one. HOPEFULLY THAT IS IT!!!

Wish me luck. But if anyone has an idea of the front parking light issue.... let me know!

 

I'm assuming you've checked the parking light sockets for voltage.

I'd back track to the next inline fender plugs that comes out of the cab. And then back to the light switch until getting wire voltage.

Orich

 

Sounds like the switch...just gotta keep going slow and get out your multimeter. Turn on the parking lights only, find the wire with voltage coming out of the headlight switch, then turn on the headlights and see if the voltage goes away.

 

It's not broke. The parking lights are supposed to go off when the headlights are turned on.
See this: Identifying 1967-1972 Ford Pickups - Page 1 of 2 - FORDification.com

About halfway down in a "Did You Know" section it says this:
"The '70-up pickups have parking lights that wrap around the side which were considered acceptable as side lights too, as long as they stayed on with the headlights. A wiring change in '70 made the parking lights stay on with the headlights, unlike the '67-'69 trucks which had parking lights that were off whenever the headlights were on. (The '70 change was in the wiring harness, not in the headlight switch, which remained the same from the previous year.)"

 

That is CRAZY! Thanks for the input. I appreciate it!

 

I didn't know that...and I think I will probably be modifying mine to stay on.

 

I didnt know that either... and i think i may do the same. But i want to at least drive it and see if the local law enforcement authorities have an issue with it!

 

I don't think they can do anything about it if that is the way it was originally produced. Like some of the older trucks that only have one taillight. It's pretty rare to see one running around like that, most of them have been upgraded to two rear lights. But a cop can't ticket you for what was allowed in the year your truck was made.

I just like lots of lights so I'll change mine, I wonder if it would be as simple as using a later model headlight switch.