Notices
1961 - 1966 F-100 & Larger F-Series Trucks Discuss the Slick Sixties Ford Truck

Tail light woes

Thread Tools
 
Search this Thread
 
Old Dec 11, 2014 | 05:47 PM
  #1  
Shadowrider123's Avatar
Shadowrider123
Thread Starter
|
Fleet Mechanic
15 Year Member
Photogenic
Joined: Oct 2007
Posts: 1,972
Likes: 103
Tail light woes

When I turn the headlights on both filaments in my tail lights come on.


The turn signals will not work when the headlights are on, but will work when the headlights are off.


I checked the harness at the tail lights. Brown is tail lights, yellow is left, green is right.


What should I check next?
 
Reply
Old Dec 11, 2014 | 07:02 PM
  #2  
ktnissen's Avatar
ktnissen
Cross-Country
10 Year Member
Joined: Sep 2014
Posts: 60
Likes: 2
I would check the grounds.
 
Reply
Old Dec 11, 2014 | 07:27 PM
  #3  
yellodog's Avatar
yellodog
Senior User
Joined: Nov 2014
Posts: 101
Likes: 0
From: nw pa
park lites are grounding thru the ts bulbs. check ground to bed and light body to bed ground.
 
Reply
Old Dec 11, 2014 | 10:09 PM
  #4  
Shadowrider123's Avatar
Shadowrider123
Thread Starter
|
Fleet Mechanic
15 Year Member
Photogenic
Joined: Oct 2007
Posts: 1,972
Likes: 103
Some progress. BTW: 1964 Flareside.


I removed the front bulbs and cleaned the contacts. They fit in the sockets very loosely, I had to fiddle with them to get them to come on. The fronts now work as parking lights and turn signals. (On a 64, the park lights go out when the head lights are on)


Am I going to have to replace the front buckets?


On the rear Im still getting both filaments lighting when the tail lights are on. Is that a ground problem? The TL brackets screw into a threaded nutsert on the bed, so I think that Im getting a good ground from the housing to the bed. I hooked battery cables to the housing and frame but that didn't do anything.
 
Reply
Old Dec 12, 2014 | 04:54 AM
  #5  
jowilker's Avatar
jowilker
Fleet Owner
25 Year Member
Joined: Jun 1999
Posts: 24,552
Likes: 74
From: Creedmoor, North Carolina
Club FTE Silver Member

To keep it simple, power has to get to the bulb filament for it to glow. If both are glowing, both are being powered, either by direct input or bad grounding back flow.

While this can be aggravating as all get out, it is usually pretty simple when you resolve it. I believe I can speak with authority on this, if it weren't simple I couldn't do it. My 66 would be a daylight driver only.


John
 
Reply
Old Dec 12, 2014 | 08:57 AM
  #6  
sseebart's Avatar
sseebart
Senior User
Joined: Jun 2014
Posts: 291
Likes: 1
From: California
Originally Posted by Shadowrider123
Am I going to have to replace the front buckets?
Not entirely sure about the park lights in your truck, but in other Fords of this vintage, the socket is replaceable by itself. Typically, the old sockets crack and get loose, as you describe. Something like this would be a replacement:

Amazon.com: Pico 5455pt All Wthr Dbl Cntct Skt - Ford: Automotive Amazon.com: Pico 5455pt All Wthr Dbl Cntct Skt - Ford: Automotive

~Steve
 
Reply
Old Dec 15, 2014 | 11:18 PM
  #7  
65F-250FATTYLEEN's Avatar
65F-250FATTYLEEN
New User
Joined: Dec 2014
Posts: 4
Likes: 0
I just went through a similar situation with my 65 F-250. It turned out to be a ground issue (my bed wasn't properly grounded) I drilled a hole in the light housing and ran it to my bed. Fixed it right up.
Hope it helps!
 
Reply
Old Dec 15, 2014 | 11:26 PM
  #8  
Shadowrider123's Avatar
Shadowrider123
Thread Starter
|
Fleet Mechanic
15 Year Member
Photogenic
Joined: Oct 2007
Posts: 1,972
Likes: 103
I added a ground wire from the bed to the frame today. The tail lights screw into the bed so I know that I have a good ground from the housing to the bed.


Could a bad ground on the fronts be causing both my rear filaments to light?


I ordered new lights for the front, DC shipped them today.
 
Reply
FTE Stories

Ford Trucks for Ford Truck Enthusiasts

story-0

Top 10 Ford Truck Tragedies

 Joe Kucinski
story-1

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

 Brett Foote
story-2

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

 Michael S. Palmer
story-3

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

 Verdad Gallardo
story-4

10 Best Ford Truck Engines We Miss the Most!

 Joe Kucinski
story-5

2026 Shelby F-150 Off-Road: Better Than a Raptor R?

 Brett Foote
story-6

2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!

 Michael S. Palmer
story-7

10 Most Surprising 2026 Ford Truck Features!

 Joe Kucinski
story-8

Top 10 Ford Trucks Coming to Mecum Indy 2026

 Brett Foote
story-9

5 Best / 5 Worst Ford Truck Wheels of All Time

 Joe Kucinski
Old Dec 16, 2014 | 04:27 AM
  #9  
jowilker's Avatar
jowilker
Fleet Owner
25 Year Member
Joined: Jun 1999
Posts: 24,552
Likes: 74
From: Creedmoor, North Carolina
Club FTE Silver Member

Don't presume all is clean on those taillight connections, verify.


John
 
Reply
Old Dec 16, 2014 | 07:06 AM
  #10  
Shadowrider123's Avatar
Shadowrider123
Thread Starter
|
Fleet Mechanic
15 Year Member
Photogenic
Joined: Oct 2007
Posts: 1,972
Likes: 103
Any idea what this is and where it plugs into?


1964 F100 292/AT


 
Reply
Old Dec 17, 2014 | 04:30 AM
  #11  
jowilker's Avatar
jowilker
Fleet Owner
25 Year Member
Joined: Jun 1999
Posts: 24,552
Likes: 74
From: Creedmoor, North Carolina
Club FTE Silver Member

I am going to suggest that it is rigged, and very likely for back up lights. I don't think that is 64 factory.


John
 
Reply
Old Dec 17, 2014 | 09:00 AM
  #12  
NumberDummy's Avatar
NumberDummy
Ford Parts Specialist
Joined: Nov 2006
Posts: 88,826
Likes: 784
From: Simi Valley, CA
Club FTE Gold Member
Originally Posted by jowilker
I am going to suggest that it is rigged, and very likely for back up lights. I don't think that is 64 factory.
Backup lamps introduced in 1967 F100/350's. With A/T, are operated by the NSS located on the steering column thru 1977.

With 3 M/T, backup lamp switch located on the bottom of the steering column under the hood. 4 M/T backup lamp switch threads into the shift tower.
 
Reply
Old Dec 17, 2014 | 09:32 AM
  #13  
Shadowrider123's Avatar
Shadowrider123
Thread Starter
|
Fleet Mechanic
15 Year Member
Photogenic
Joined: Oct 2007
Posts: 1,972
Likes: 103
Since no one recognizes it, I will take it off and see if it is connected to anything in the column.


It looks to me like it belongs there and it fits the column.


I don't have backup lights, but I don't think the flare is the original bed since it is in perfect condition and the truck is a CC.
 
Reply
Old Dec 17, 2014 | 11:09 AM
  #14  
SuperSabre's Avatar
SuperSabre
Laughing Gas
Joined: Dec 2010
Posts: 1,091
Likes: 14
From: Tucson, Arizona
I may be mistaken, but didn't Number Dummy just identify that as your neutral safety switch?
 
Reply
Old Dec 17, 2014 | 11:39 AM
  #15  
banjopicker66's Avatar
banjopicker66
Postmaster
Joined: Apr 2002
Posts: 3,613
Likes: 6
From: Coal country
Originally Posted by SuperSabre
I may be mistaken, but didn't Number Dummy just identify that as your neutral safety switch?
SS, I understood that ND was not identifying that connector as the NSS, but giving out general information about backup lamps. Perhaps I misunderstood?

The NSS uses a different plug connector than what is in the picture.

I believe the owner's truck uses the same turn signal switch as '65 and '66, possibly later.
If so, then that 2-wire plug is for the taillights, according to the electrical diagrams that I have.

John - Banjo -
 
Reply



All times are GMT -5. The time now is 05:13 AM.

story-0
Top 10 Ford Truck Tragedies

Slideshow: Top 10 Ford truck tragedies.

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


VIEW MORE
story-1
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-2
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-3
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-4
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
story-5
2026 Shelby F-150 Off-Road: Better Than a Raptor R?

Slideshow: first look at the 810 hp 2026 Shelby F-150 Off-Road!

By Brett Foote | 2026-05-12 12:50:07


VIEW MORE
story-6
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!

Slideshow: Everything You Need to Know about the 2027 Super Duty Carhartt Package!

By Michael S. Palmer | 2026-05-07 17:51:06


VIEW MORE
story-7
10 Most Surprising 2026 Ford Truck Features!

Slideshow: 10 most surprising Ford truck options/features in 2026.

By Joe Kucinski | 2026-05-05 11:17:22


VIEW MORE
story-8
Top 10 Ford Trucks Coming to Mecum Indy 2026

Slideshow: Here are the top 10 Fords coming to Mecum Indy 2026.

By Brett Foote | 2026-05-04 13:49:49


VIEW MORE
story-9
5 Best / 5 Worst Ford Truck Wheels of All Time

Slideshow: The 5 best and 5 worst Ford truck wheels of all time

By Joe Kucinski | 2026-04-29 16:49:01


VIEW MORE