I have an '85 F-150, and I have a problem with the lights.

Working lights:
Front/Rear Turn Signal Lights
High-Beam/Low Beam Headlights
Brake Lights

Non-Working lights:
Rear Running Lights
Dash Lights
Front Side Orange Bar Lights


If you move the stick just right, right before you turn them off, the rear lights start to work, but no dash lights or front side orange bar lights.

I replaced the headlight switch, but it's the same exact problem. One of my friends said it was the way that I put the stick in the headlight switch.


What do you guys think? I've looked at all of the fuses multiple times, and they are all okay.

 

C'mon, Paul, you gotta put some work into this too, ya know.

This is the 3rd thread from you in the last month about this exact problem and you don't
give much feedback other than the fuses are OK to what people have offering here.

Nobody here can tell you exactly what's wrong, the best we can do is point you at
places to look. Nobody is going to spoon-feed you the exact answer because nobody
has seen your truck, traced the wires and diagnosed this problem. THIS IS YOUR JOB.

Some time ago, you were saying that operating the headlight switch was causing noises
to come out of the radio, I've twice hinted that this is a place to go looking for problems
but you've said nothing.

So, I shall make stronger hints:

DISCONNECT AND REMOVE THAT RADIO AND SEE WHAT THAT DOES TO
YOUR PROBLEM

I think I've said the following in the past:

The tail lights as well as the front marker lamps all operate from the same circuit, a dark
brown wire that feeds them all.

Dash & cluster lights are dimmable and are fed by a light blue/red stripe wire. Find
that wire under your dash, trace it and look for problems. The factory radios had
incandescent bulbs to light the dial & buttons powered by this wire, that is the ONLY
way the headlight **** should affect a radio.

IIRC some time ago you said bouncing of the truck would make your lights work/not
work. This points to bad grounds/bad connections/bad sockets/bad bulbs (crossed
filaments). Investigate those possibilities, would ya? Clean all the connections, replace
sockets if needed, burned-out bulbs, etc. Report what you find.

It is entirely normal for different lights to come on/go off when a mechanical switch is
oriented in exactly the right position.

It is NOT normal for the radio to audibly react to the headlight ****, SOMETHING IS
WRONG THERE, TAKE IT APART AND LOOK! Remove that radio, if it solves your
problem(s) we can tell you how to re-connect it properly later.

But ya can't just keep posting the same problem three times in one month and ignoring
people's attempts to help you. You're a smart guy, go figure it out.

https://www.ford-trucks.com/forums/1...t-working.html
https://www.ford-trucks.com/forums/1...ht-issues.html

 

I did that this morning. Same light problem, so, it is not the radio.

Also, that sound that it made? It only did it once, I could not get it to do it again.


I traced this wire, as many others, and the wires are fine.


I said that when I hit the bumps, my lights did come on and go off sometimes. This problem is due to my headlight switch. If you move the stick just right, the back lights turn on, yet when you lightly tap it or do anything, they turn back off. So, it is none of the bulbs or sockets.



Like I said, it isn't the radio, and the sound that it made, well it only happened once. I took out the radio this morning, and still had the same problem.




SO! I believe that it has something to do with the headlight switch, since that is the only possible reason that it could be not working, since I have canceled out everyone's answers to the problem so far.

The switch has been replaced, but the problem is still in the truck. Yes, I know, that would make it sound light it's something other than the switch, but if I move the switch just right, the lights turn on.

Hence why I say it is the switch.


Could it have been the way I put the stick into the switch?

 

I don't remember if I answered you before, but it sounds like you have two problems.

1. Your running lights power feed to the headlight switch is dead. This is a tan/white wire going to the switch. This will be a fuse problem, or the tan/white wire has melted and burnt in two, which is known to happen once in awhile. When you are pulling the switch out half-way and making the rear lights work, you are putting the switch in a place it's not supposed to be, and crossing up contacts inside the switch. The headlights have a separate power wire that is good, and you are making this power cross over and power the running light circuit inside the headlight switch.

2. When you are crossing the contacts over inside the headlight switch, all the outside running lights should work. Like was said, all the outside running lights are fed by the brown wire. So once you get the power feed problem fixed on the tan/white wire, if the front lights still won't work, you will have to start checking connections to see why the front lights are not working.

 

Quote:

Originally Posted by Wicked Endings

If you move the stick just right, the back lights turn on, yet when you lightly tap it or do anything, they turn back off. So, it is none of the bulbs or sockets.

Like Franklin just mentioned, when you move the switch into that "just right"
position and make things come on, you are, in fact, crossing wires and
feeding power to wires in a way that doesn't happen in normal operation.

This gets complicated by the fact that multi-filament bulbs are fed by
different circuits; in the case of the rear lamps, the brown wire powers one
filament in that bulb while a different wire is powered by the brake & turn
signal switches (which lights the other filament).

So, when the headlight switch is in that "just right" position, which filaments
are getting power? Answer: You don't know unless you were to investigate
further.

Point being, just because lights come on when the switch is in an errant
position doesn't at all exclude possible problems with bulbs, sockets &
wiring. I'm suggesting you look into those items as they could, at the very
least, be contributing to your problem (which may be originating from
multiple sources).

Bouncing causing things to come on/go off can be indicative of problems in
places besides the headlight switch, too. In particular, connections that are
exposed to the elements become corroded over time and will work or not
work depending on the phase of the moon; busted filaments that are crossing
circuits are also highly suspect, as are corroded ground connections (to name
a few).

Quote:

Originally Posted by Wicked Endings

Hence why I say it is the switch.

Not so fast there, buddy. I explained why above.

This would be a great place for a Yoda quote.

Quote:

Originally Posted by Wicked Endings

Could it have been the way I put the stick into the switch?

I can't see that, the stick goes in only one way, it's pretty hard to mess up.

Given your switch is brand new (and presumably known to be good)
combined with it behaving the exact same as your other switch says the
chances are pretty dang high the problem(s) exist(s) someplace else.

 

The open in the tan/white wire could be at the connector the headlight switch... they fail there pretty often

 

Okay.

I will go and look at all of the bulbs, wires to and from the sockets, and the wires that connect to the headlight switch.

 

Okay, so...

I went back and looked at the radio again, and not only did I disconnect it this time, I took out the entire thing. All the wires, everything. It seems that the person that put it in just hacked into the original wires....


So, now that it's back to the original wires, I went and looked down at the fuses once again.


A blown fuse.





Anyways, so after that blown fuse was replaced, and the radio and all the wires were gone, I went to go turn on the lights.


Running lights in the rear finally turned on. So, now I have headlights, brake lights, running lights...

Still no dash lights, and no license plate lights.


But wait, there's more.


I went to turn the turn signal on, worked fine.

I turned on the lights, turned the turn signal on..

Lights went out. Which meant the fuse was blown again.


Okay. So, lights do work, but when I turn on the turn signal lights with the lights on, it blows the fuse and turns the rear lights off.

JUST THE REAR LIGHTS, NOTHING ELSE.


So... what now?

 

'k, man, you're making good progress, but I'm asking you to be precise
exact in your descriptions, OK? headlights, parking lights, brake lights all
are on different circuits and it really helps us to know exactly which lamps
you're referring to:

Quote:

Originally Posted by Wicked Endings

I turned on the lights, turned the turn signal on..

Lights went out.

You're talking the rear marker lamps and not the headlights or any other
lights, correct? The statement "lights went out" would imply the
HEADLIGHTS went out.

So, you're saying when you turn on the headlights (which includes the marker
lamps) and then turn on the turn signal, the rear marker lamps go out?

And a fuse blows? Which fuse?

And the front & side marker lamps don't go out at the same time?

Again, WHICH fuse blows?




In any case, if just the rear markers go out while the front remain lit AND
THE PARK/TAIL LAMPS FUSE AS SHOWN ABOVE HAS NOT BLOWN, your
wiring is still jacked, somebody has set up the rear marker lamps (normally
fed by the dark brown wire) to get power from someplace else and this is
interfering with the proper operation of the turn signal switch.

Or so it seems to me, somebody else may be able to offer more insight or
point out where I'm wrong but please confirm the details I asked about, OK?

 

License plate lights are fed by the same wire as the rear running lights. Your rear running lights are working, so that means power is back there, you just have a problem with the license light wiring, so concentrate at the rear bumper area for that problem.

Dash lights have their own fuse, check that and make sure it's good. If it's good, twist the headlight **** and see if they come on.

Double check that fuse is blown. If it's not, and they work with the signal off, you may have a grounding problem.

 

check and see if someone wired in a trailer harness. it could be shorting out, and causing some of your problems.

 

Quote:

Originally Posted by dustybumpers

check and see if someone wired in a trailer harness. it could be shorting out, and causing some of your problems.

This is a great suggestion, hack jobs of trailer wiring kits can cause all kinds of
problems....

 

This diagram is wrong with one respect.

The left side is 1980 only, and the right is 1981-1986.

 

Okay.

I have great news.


Today, I tore apart the entire interior of the truck.

I mean, everything, all the panels, dash, everything was on the ground outside.

I went one by one, making sure no open wires, made sure all the connections were tight. Any wires that weren't attached to anything, that weren't of any use, I took out.

After that, I went and cleaned the connections from my headlight switch and put that back in. I then went through and replaced every single fuse with a new fuse. After that, I went and checked to see if all of the bulbs in the dash were O.K.

After doing all that, I put the entire thing back together (Minus the radio) and then turned the truck on.

I pulled the headlight switch on, looked at the back.

LIGHTS WERE ON!

Looked in the front.

LIGHTS WERE ON!

Turned on the turn signals.

ALL OF THE LIGHTS WORKED AND DIDN'T BLOW OUT.

Looked inside at the dash.

ALL OF THE LIGHTS WORKED!



So.. the light problem I have had since my truck was bought.. is now fixed.


Thank you EVERYONE for all of your help.


Without you, my truck would not be where it is today.