Notices
1973 - 1979 F-100 & Larger F-Series Trucks Discuss the Dentsides Ford Truck
Sponsored by:
Sponsored by: Moser

electrical problem I'm stumped

Old Dec 16, 2004 | 08:49 PM
  #1  
whd507's Avatar
whd507
Thread Starter
|
Posting Guru
25 Year Member
Joined: Jun 1999
Posts: 1,172
Likes: 2
From: SW Missouri
electrical problem I'm stumped

1976 F-series.

the brakelights dont work, neither do the front turn signals, or hazards. I thought it was the wiring in the steering column, but after swapping columns, there was no difference. there is no power to the brake light switch, and if I jump power to the brake light plug, it shorts out.
all running lights work. headlights work, everything else works. turn signal indicators work, with the rear turn signals.


any Ideas?
 
Reply
Old Dec 16, 2004 | 09:30 PM
  #2  
SwOkcOffRoader's Avatar
SwOkcOffRoader
Postmaster
20 Year Member
Joined: Jul 2003
Posts: 2,544
Likes: 2
From: okc
that happened to my F-250, same lights and all...tried wiring up the brakes like you said and it burnt the brake wire completly through the wiring harness, it was quite the mess, turned out my wiring harness running to the rear of the truck fell on the muffler and melted all the wires, melting the brake wire to the side of the muffler, which explained why it shorted out on me.....id check all the wiring coming out of the cab...........
 
Reply
Old Dec 17, 2004 | 04:28 AM
  #3  
Torque1st's Avatar
Torque1st
Posting Legend
Joined: Sep 2001
Posts: 30,255
Likes: 37
There is a tech article on lights etc here. Check the link to the right ==>
 
Reply
Old Dec 17, 2004 | 08:50 AM
  #4  
whd507's Avatar
whd507
Thread Starter
|
Posting Guru
25 Year Member
Joined: Jun 1999
Posts: 1,172
Likes: 2
From: SW Missouri
yeah I looked there, he had a diffeent issue. I'm going to find the wiring schematic today...


then I get the joy of replacing the heater core in a truck that has been converted to factory air... ugh...

rear signals work, so I know the rear wiring is ok, the parking lights all around work, and the headlights work, but the front signals and hazards dont. I thought that the turn signal switch seperated the front and rear signals, so the brake lights will work.

so my plan is to trace the source of power to the brakelight switch, and front flashers.(and hazards)
 

Last edited by whd507; Dec 17, 2004 at 08:57 AM.
Reply
Old Dec 18, 2004 | 01:58 PM
  #5  
76Forder's Avatar
76Forder
Senior User
Joined: Nov 2004
Posts: 133
Likes: 1
From: NE Oklahoma
did you check the lil flasher fusebulb thing? or 76 didnt have em did they?
 
Reply
Old Dec 18, 2004 | 03:48 PM
  #6  
ranger429's Avatar
ranger429
Logistics Pro
Joined: May 2003
Posts: 4,238
Likes: 21
From: Northern Illinois
Originally Posted by 76Forder
did you check the lil flasher fusebulb thing? or 76 didnt have em did they?
Sure they did, flashers date back to the candle!!

whd, is it the brake lights that don't work as stated or is it the rear turn signals that don't work? Or is it both.

If they are not lighting up at all it will not be the flasher, I presume you have checked the fuses and bulb's?

and if I jump power to the brake light plug, it shorts out.
Are you depressing the brake pedal when you try this?

turn signal indicators work, with the rear turn signals.
The turn indicator's flash in the rear but you have no brake light's?

Never mind, just read your second post, check your harness at the firewall. Might be a bad connection there.
 
Reply
Old Dec 18, 2004 | 09:01 PM
  #7  
whd507's Avatar
whd507
Thread Starter
|
Posting Guru
25 Year Member
Joined: Jun 1999
Posts: 1,172
Likes: 2
From: SW Missouri
I changed the steering column, to a tilt unit I had lying around,, and that allowed the front signals to work, as well as the hazards. all the turn signals worked, until I tried the brakes, then the right rear signal acted up, and the brakes worked very dim. the switch got hot, so its to the very rear harness next. the harness from the firewall to the rear bumper checks out ok . the rear signal worked fine yesterday, and today before I tried the brakes.


but at least there is progress...
 
Reply
Old Dec 18, 2004 | 09:09 PM
  #8  
fearfactory's Avatar
fearfactory
Senior User
20 Year Member
Joined: Dec 2004
Posts: 182
Likes: 0
From: Central,IL
Check for bad grounds.
 
Reply
FTE Stories

Ford Trucks for Ford Truck Enthusiasts

story-0

10 Ugly Ford Trucks That We Still Kinda Love

 Joe Kucinski
story-1

10 Things Every Truck Owner NEEDS (2026 Edition)

 Michael S. Palmer
story-2

Rezvani's Latest Post-Apocalytic Monster Is a Ford F-150 Raptor Underneath

 Verdad Gallardo
story-3

Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer

 Joe Kucinski
story-4

2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)

 Brett Foote
story-5

Top 10 Ford Truck Tragedies

 Joe Kucinski
story-6

AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make

 Brett Foote
story-7

Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!

 Michael S. Palmer
story-8

Ford's 2001 Explorer Sportsman Concept Looks For a New Home

 Verdad Gallardo
story-9

10 Best Ford Truck Engines We Miss the Most!

 Joe Kucinski
Old Dec 18, 2004 | 11:57 PM
  #9  
whd507's Avatar
whd507
Thread Starter
|
Posting Guru
25 Year Member
Joined: Jun 1999
Posts: 1,172
Likes: 2
From: SW Missouri
I did that first. this truck has no rust, and generally good wiring condition. I suspect a splice in the rearmost taillight harness is the culprit.
 
Reply
Old Dec 30, 2004 | 10:55 AM
  #10  
RDON's Avatar
RDON
Senior User
Joined: Nov 2004
Posts: 195
Likes: 0
From: Wilton, Ca
It sounds to me that the trouble is in the brake switch. Your turn signal and brake are the element in the bulb,So if the turn is working at all means you are getting current to the rear.With a test light I would check the brake switch.You probley know this,But in case one side is hot and the other is hot when the brake is deprested.If this checks out then it has to be a groung.A bad ground will cause it to be dim and work off an on. If the splices are a mess once you have the problem solved you should solder the splices.I have had a lot of trouble with wire conectors (corrosion)If you have them that could be some of your trouble also
I hope this helps. I had a lot of trouble with the brake lights on my 5th wheel,So I know what you are going through
Don
 
Reply
Old Dec 30, 2004 | 11:26 AM
  #11  
whd507's Avatar
whd507
Thread Starter
|
Posting Guru
25 Year Member
Joined: Jun 1999
Posts: 1,172
Likes: 2
From: SW Missouri
I found it, it was a bad trailer wiring connector. when the previous owner added a 4-pin connector, he wrapped it around the rear corssmember, and wedged it against the tank edge. both the green and yellow wires were bared. I guess it wasnt enough of a short to affect each individual turn signal, but when the brakes were applied, it was too much, (?) but when I repaired the areas wiring, and added a 7-pin combo plug, the front signals, hazards and the brakes work. (!!??!!)
 
Reply
Old Dec 30, 2004 | 11:31 AM
  #12  
SwOkcOffRoader's Avatar
SwOkcOffRoader
Postmaster
20 Year Member
Joined: Jul 2003
Posts: 2,544
Likes: 2
From: okc
sounds similar to what i was saying above, only without melting on the muffler....glad you worked it out and got lights again....its always refreshing to know someone conquered a Ford truck wiring puzzle....
 
Reply


Thread Tools
Search this Thread

All times are GMT -5. The time now is 12:40 PM.

story-0
10 Ugly Ford Trucks That We Still Kinda Love

Slideshow: 10 ugly Ford trucks that we still kinda love.

By Joe Kucinski | 2026-06-03 09:51:16


VIEW MORE
story-1
10 Things Every Truck Owner NEEDS (2026 Edition)

Slideshow: the best gifts for dads & grads

By Michael S. Palmer | 2026-06-03 09:39:23


VIEW MORE
story-2
Rezvani's Latest Post-Apocalytic Monster Is a Ford F-150 Raptor Underneath

Slideshow: Called the Fortress, the 850-horsepower pickup combines Raptor underpinnings with military-inspired features, survival equipment, and a starting price of $285,000.

By Verdad Gallardo | 2026-05-30 18:33:59


VIEW MORE
story-3
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer

Slideshow: 10 most expensive Ford trucks ever sold on Bring a Trailer.

By Joe Kucinski | 2026-05-27 16:24:34


VIEW MORE
story-4
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)

Here's everything that has changed for the latest model year.

By Brett Foote | 2026-05-27 16:17:28


VIEW MORE
story-5
Top 10 Ford Truck Tragedies

Slideshow: Top 10 Ford truck tragedies.

By Joe Kucinski | 2026-05-18 19:34:33


VIEW MORE
story-6
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make

And it might be even better than that.

By Brett Foote | 2026-05-18 19:26:42


VIEW MORE
story-7
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!

Slideshow: Does lowering an F-150 Lobo RUIN the ride quality?

By Michael S. Palmer | 2026-05-18 19:20:37


VIEW MORE
story-8
Ford's 2001 Explorer Sportsman Concept Looks For a New Home

Slideshow: Ford's bizarre fishing-themed Explorer concept has resurfaced after spending decades largely forgotten.

By Verdad Gallardo | 2026-05-12 18:07:46


VIEW MORE
story-9
10 Best Ford Truck Engines We Miss the Most!

Slideshow: The 10 best Ford truck engines we miss the most.

By Joe Kucinski | 2026-05-12 13:09:47


VIEW MORE