1971 F100 Horn wiring!?

[Davep]

Ive just bought a 71 F100, farm used! It has no horn wiring at all! I cant understand the wiring Diagram I have!, as it shows a wire from the Voltage regulater(Yellow) Can anyone help?

[price2757]

1 wire from voltage regulator to horn relay (I ran mine from the starter relay. I can't tell you what color wire its supposed to be as mine had been removed). 1 from relay to horns. 1 from steering column to horn relay. The one coming out of the steering column is blue with yellow stripe if I remember correctly. Make you you have the horn contact brush in it's spot under the steering wheel. Search this section. There is all sorts of help, pics and diagrams to assist you.

[basketcase0302]

Davep,

Odd that I couldn't find one for the 71, (I know our 71 and 72's have a little different wiring on a few components).
Here's a diagram on the 72 models wiring showing a yellow wire feeding power to them, you might want to give it a shot.
http://www.fordification.com/images/sch ... _quick.jpg
If nobody pipes in I'll try to get the color from my 71 F-350 for you tomorrow, (raining like cats and dawgs here).

Basketcase

[Davep]

Thanx guys, thats great help, Apreciate it!

[Thunderfoot]

Davep,

Odd that I couldn't find one for the 71, (I know our 71 and 72's have a little different wiring on a few components).
Here's a diagram on the 72 models wiring showing a yellow wire feeding power to them, you might want to give it a shot.
http://www.fordification.com/images/sch ... _quick.jpg
If nobody pipes in I'll try to get the color from my 71 F-350 for you tomorrow, (raining like cats and dawgs here).

Basketcase

FYI, that diagram is WRONG on some parts of the horn wiring... It shows the Horn button wire going to the instrument lights and the instrument lights to the horn signal wire.

Here is what I'm talking about;

This is how it is now and it is WRONG!!! No way - No how does the horn wire come from the light switch or the horn button go to the instrument lights...


This is how it is supposed to be.


This is the more simple diagram and is the same for the 71-72 trucks. http://www.fordification.com/images/sch ... ircuit.jpg

[rjewkes]

oddly TF i think that is closer to the truth in that diagram, as in my 72(and it may be becuase i have a 78 CC column)

As when i turn the engine over, or hit the horn or turn the lights off real fast, the turn signal lights on the dash lightup real quick.

[Wes]

OT a little bit.
I'm not surprised 1 bit, good catch Thunderfoot
When I attended Ford training, the instructor set up bugs in vehicles for us to practice our lessons on. Most of the bugs, esp in the electrical lessons,
were on years and makes that had incorrect information in the published service manual. I was surprised at how often it occurred. We use the Fleet Ford tech web site to double check info that doesn't seem to match the truck.

[Davep]

Got it! I never thought that wiring diag was wrong!

[Thunderfoot]

oddly TF i think that is closer to the truth in that diagram, as in my 72(and it may be becuase i have a 78 CC column)

As when i turn the engine over, or hit the horn or turn the lights off real fast, the turn signal lights on the dash lightup real quick.

rjewkes, There is no way the horn activation (pushing the horn button) comes from the light switch... and no wiring is routed from one to the other.

On your problem that acts like a bad ground connection in your wiring, probably something to do with the way the 78 column was wired in. Bad grounds will make lights and things activate that have nothing to do with each other, as the electrical current tries it's hardest to find a path through something to make a complete circuit (these can be very difficult to find).

The Dent columns also have the Hazard switch mounted/wired in the column. (I kind of suspect something mis-wired here is causing your problem)
Also, if I remember correctly, the ground for the horn on the dent columns is done through an added ground wire in the column instead of using the steering shaft itself, like the older trucks do...

[rjewkes]

TF I beleiver Your Right. I hope to swap back to a bump colum or atleast to a bump tss.