That diagram still shows one power feed to the switch, and it is split internally inside the switch going to the running lights and the headlights.

What is a signal stat?

 

U cant ask that. Thats my question, lol.
I know it doesnt look factory but I dont know why its there. It says signal stat 192. I have a wire going directly from the positive terminal of the solonoid to the signal stat with an inline 20 amp fuse, white wire. The brown wire on top goes to the taillights/parking lights. The other brown wire goes into the harness that goes through the fire wall. Im assuming to the headlight switch. Have full 12v power at the white wire but only 6mv at the other terminals. With the headlights on i get 39mv at the lower brown wire. Could this be my problem? Could this have been for trailer lights?

 

That is a added on bosh type relay. It could have been for something like trailer lights. Here is a schematic and the terminal layout



If you want to see what it's supposed to do, take the white wire off and take the heavier brown wire off and touch them together. If there is a problem on the large brown wire it should blow the 20 amp fuse.

 

So there should be power to the heavier brown wire through the ss relay? That wire goes directly to the taillights.
I checked the headlight switch with the headlights on and there is 12v at the black wire, 39mv at the yellow wire, and 6mv at the brown wire, same as at the signal stat.
If i have 12v going into the switch and only 39mv coming out to the headlights, is this right?

 

If im not using trailer lights does the signal stat need to be there? If not should i just rewire without it? If i decide to use a trailer in the future would i need it?
This seems to be a wiring nightmare. Im really not looking forward to rewiring the whole truck but there were so many things on this truck that were rigged that it scares me.

 

The "signal stat" is a relay. You can see the one wire bolts to ground. The other small brown wire is the trigger wire for the relay. When the small brown wire gets power, the relay puts the large brown wire and the white wire together.

Where does the small brown wire on the relay come from?

 

Its hard to tell wirhout ripping the harness out but i believe it comes from the headlight switch. It looks like the brown wire was cut and plugged into 2 of the termals on the relay so i tried putting the 2 brown wires back together with the headlights on but nothing. Im thinking it is definitely the switch. Forgot to mention, the horn doent work either and see its on the wiring diagram at the headlight switch. I cant find a horn relay, where would this b located? I think some models didnt have a relay.
Thanx for your explanation of the signal stat. Do i need to have it with trailer lights? Or can they b wired directly if i decide to use a trailer in the future?

 

You can wire them directly. If you want to lighten the load you can change some of your marker lights to LED.

 

Ok, once again, problem not solved. I knew this could b a nightmare.
Got a new light switch, put it in, and same as before, headlights work but no running/parking lights.
Now i notice an intermittent buzzing noise coming from the steering column until i disconnect the battery. My model doesnt have a horn relay and the horn doesnt work.
What could this possibly be?

 

See if you have a fuse for the horn(it may have a few other things on it also). See if the buzzing goes away when you pull the horn fuse out.

 

No fuse labled for horn. Now that i listen closer it sounds like a click in the directional switch and then a ping in the light switch as a response, repeating over and over.

 

According to this diagram, the horn and speed control are fed from the circuit breaker and power feed that feeds the headlight switch. Now that you have replaced the headlight switch, you have power in the steering column doing something. Whether it be good or bad I don't know, but I am thinking your old headlight switch was bad.

http://www.fordification.net/tech/im...aster_1of9.jpg

 

I wonder if this truck used to have speed control. The steering wheel has been replaced. Where would it have been located? That would make sence if it did and the horn relay is in the column. Is that correct?

 

No room in the column for the horn relay. It's usually mounted under the dash somewhere.

 

Just started to pull the wheel and found the horn wire was shorting out and causing the clicking noise which kinda sounds like a relay. Horn doesnt work, just get that click when i press it.