69 F250 Wire Problems/tail lights HELP!!
Thread Starter
|
Elder User
Joined: Feb 2002
Posts: 586
Likes: 0
From: Covington usa
69 F250 Wire Problems/tail lights HELP!!
HELP!! I just bought my 69 F250 from my oldest son who bought it from my son-in-law. Anyway here's the help I need. I found that the right rear tail light didn't work...no biggy. But if you put on the right turn signal the right front come on amnd the left rear do as well. I replaced the right rear bulb but that didn't help. Neither son said thte had switched any wires so I'm wondering if anyone has seen or heard of this problem.
Posting Guru
Joined: Jun 1999
Posts: 2,415
Likes: 3
From: Comox Valley, Canada
69 F250 Wire Problems/tail lights HELP!!
Sounds like the famous "floating ground syndrome". A ground is bad somewnere. So check the grounds , black wires, at all the bulb sockets. May even have to replace some sockets, they are cheap 
As they get corroded over the years and cause neat problems like you have.
Sparky
ps
Out of curiosity what happens to the lights when you turn on the left turn signal, or just the parking lights or step on the brakes ???
As they get corroded over the years and cause neat problems like you have.Sparky
ps
Out of curiosity what happens to the lights when you turn on the left turn signal, or just the parking lights or step on the brakes ???
Thread Starter
|
Elder User
Joined: Feb 2002
Posts: 586
Likes: 0
From: Covington usa
69 F250 Wire Problems/tail lights HELP!!
Well I'll check the grpunds... the other side just don't work... for brake or stop...I replaced the bulb and still no go... I'll look at the grounds and replace the sockets. Can they be bought at the local NAPA or Ford store?
Posting Guru
Joined: Jun 1999
Posts: 2,415
Likes: 3
From: Comox Valley, Canada
69 F250 Wire Problems/tail lights HELP!!
The sockets should be avaiable at NAPA......here they are in the Canadian Tire "help" aisle
Just a clarification when you turn on the right signal light the left rear light comes on or does it actually flash?
If it flashes it could be a bad turn signal switch, this could also cause the right brake light not to work as the brake light circuit goes thru the signal light switch.
Have you checked for power at the right rear light? Does the right rear parking/running light work? If so the ground is most likely OK there, as it is a common ground for both the turn signal, brake and parking lights at each socket. The brake light and turn siganl actually use the same filament in the bulb. The other filament is for the parking light.
Sparky
Just a clarification when you turn on the right signal light the left rear light comes on or does it actually flash?
If it flashes it could be a bad turn signal switch, this could also cause the right brake light not to work as the brake light circuit goes thru the signal light switch.
Have you checked for power at the right rear light? Does the right rear parking/running light work? If so the ground is most likely OK there, as it is a common ground for both the turn signal, brake and parking lights at each socket. The brake light and turn siganl actually use the same filament in the bulb. The other filament is for the parking light.
Sparky
Junior User
Joined: Feb 2002
Posts: 75
Likes: 0
69 F250 Wire Problems/tail lights HELP!!
[updated:LAST EDITED ON 13-Feb-02 AT 10:34 AM (EST)]I am having a similar problem with a '71 F-250 CS, only not the tail lights. The driver side rear brake light will not work. Changed the bulb, no dice. Turn signal switch would not self cancel, so I bought the repair kit from NAPA to fix that problem, hoping it woud solve the brake light problem. That didn't help either. The front bulbs work normally. Any ideas? Oh, the back-up lights work fine and I have 12.2 volts to the socket on the tail light (tail light works).
Moderator
Joined: Jan 2001
Posts: 57,025
Likes: 2,758
From: Virginia
69 F250 Wire Problems/tail lights HELP!!
Find out what color the wire is that goes to the brake light that doesn't work. That wire color should be present in the harness going up the steering column. See if you have voltage at the steering column on this wire when the brake is pushed. If not, it's probably the turn signal switch.
Junior User
Joined: Feb 2002
Posts: 75
Likes: 0
69 F250 Wire Problems/tail lights HELP!!
Franklin2, Thanks for the tip. I will investigate further when it stops raining here (outdoor workshop 
).
).Trending Topics
Posting Guru
Joined: Jun 1999
Posts: 2,415
Likes: 3
From: Comox Valley, Canada
69 F250 Wire Problems/tail lights HELP!!
Does the drivers side turn signal work in the rear? The reason I ask is the turn signal and brake light use the same wire from the turn signal switch back to the bulb, the same filament in the bulb and the same ground.
So if the turn signal works and the brake light doesnt the problem is in the turn signal switch. Unless both brake lights dont work then it could be the brakelight switch, fuse or wiring to the turn signal switch as well.
I have found most times this problem comes up, one dead brake light, the problem is inside the turn signal switch.
Sparky
ps
I just noticed your truck is a 71, I have never owned a pre 73 truck, yet , but I seem to remember that they are wired the same.
So if the turn signal works and the brake light doesnt the problem is in the turn signal switch. Unless both brake lights dont work then it could be the brakelight switch, fuse or wiring to the turn signal switch as well.
I have found most times this problem comes up, one dead brake light, the problem is inside the turn signal switch.
Sparky
ps
I just noticed your truck is a 71, I have never owned a pre 73 truck, yet
, but I seem to remember that they are wired the same.FTE Stories
Ford Trucks for Ford Truck Enthusiasts
Top 6 Best Deals Available on New Fords & Lincolns Right Now
Brett Foote
This Hennessey Takes the Expedition Tremor's Off-Roading Capability to the Next Level
Verdad Gallardo
Top 10 Fords at 2026 Carlisle Ford Nationals
Joe Kucinski
3 Best / 3 Worst Parts of Modern Ford Ownership
Brett Foote
10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches
Pouria Savadkouei
Every 2026 Ford Engine Explained
Brett Foote
10 Ugly Ford Trucks That We Still Kinda Love
Joe Kucinski
10 Things Every Truck Owner NEEDS (2026 Edition)
Michael S. Palmer
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath
Verdad Gallardo
Junior User
Joined: Feb 2002
Posts: 75
Likes: 0
69 F250 Wire Problems/tail lights HELP!!
I must have an intermittant problem. I moved the truck across the yard yesterday and re-checked the brake and turn signal lights. Now everything works! What's going on here?
New User
Joined: Jan 2008
Posts: 0
Likes: 24
69 F250 Wire Problems/tail lights HELP!!
I think it's obvious,
Elvis is working on your truck at night.
Dennis https://www.ford-trucks.com/user_gallery/sizeimage.php?&photoid=1733&.jpg
Please Don't Ask Me Any Tough Questions As:
"I'm Saving My Memory For When I Develop Alzheimer's"
78 F-150 429CJ,Silver
w/Explorer Pkge.
641/2-Mustang 260,Pre-World's Fair Car.
64-Fairlane500 S/C waiting for a 390-4spd.
68-Mustang 289-Sunlit Gold 80,892Mi
78-Buick LeSabre 403 4V
84 Volvo DL Wagon
Elvis is working on your truck at night.
Dennis https://www.ford-trucks.com/user_gallery/sizeimage.php?&photoid=1733&.jpg
Please Don't Ask Me Any Tough Questions As:
"I'm Saving My Memory For When I Develop Alzheimer's"
78 F-150 429CJ,Silver
w/Explorer Pkge.
641/2-Mustang 260,Pre-World's Fair Car.
64-Fairlane500 S/C waiting for a 390-4spd.
68-Mustang 289-Sunlit Gold 80,892Mi
78-Buick LeSabre 403 4V
84 Volvo DL Wagon
Thread Starter
|
Elder User
Joined: Feb 2002
Posts: 586
Likes: 0
From: Covington usa
69 F250 Wire Problems/tail lights HELP!!
If I use the right turn (up) the front trun signal will light-up (correctly) and the lfet rear will go on and blink. The right rear lights do work.. any suggestions
Junior User
Joined: Feb 2002
Posts: 75
Likes: 0
69 F250 Wire Problems/tail lights HELP!!
Without blaming "the King" for this weird problem, I think Sparky's suggestion is right on. I seem to be having a grounding problem, since I can find no direct ground connection between the frame and the battery or the battery and the body. Although the light sockets are all grounded individually, they are grounded to the body or the bed and not to the battery itself.
My question is this: Did these trucks ever have a ground cable or strap to connect the engine to the frame? My negative battery cable goes directly to the engine block, but I can find no cables or straps to the frame or body. I will add one myself, but if one is missing to start with, it would explain quite alot.
Thanks everyone for your input so far :-) .
My question is this: Did these trucks ever have a ground cable or strap to connect the engine to the frame? My negative battery cable goes directly to the engine block, but I can find no cables or straps to the frame or body. I will add one myself, but if one is missing to start with, it would explain quite alot.
Thanks everyone for your input so far :-) .
New User
Joined: Jan 2008
Posts: 0
Likes: 24
69 F250 Wire Problems/tail lights HELP!!
There is usually a braided wire from the rear of the head right bank
to the Firewall.
And another one from the hood to the firewall.
Dennis https://www.ford-trucks.com/user_gallery/sizeimage.php?&photoid=1733&.jpg
Please Don't Ask Me Any Tough Questions As:
"I'm Saving My Memory For When I Develop Alzheimer's"
78 F-150 429CJ,Silver
w/Explorer Pkge.
641/2-Mustang 260,Pre-World's Fair Car.
64-Fairlane500 S/C waiting for a 390-4spd.
68-Mustang 289-Sunlit Gold 80,892Mi
78-Buick LeSabre 403 4V
84 Volvo DL Wagon
to the Firewall.
And another one from the hood to the firewall.
Dennis https://www.ford-trucks.com/user_gallery/sizeimage.php?&photoid=1733&.jpg
Please Don't Ask Me Any Tough Questions As:
"I'm Saving My Memory For When I Develop Alzheimer's"
78 F-150 429CJ,Silver
w/Explorer Pkge.
641/2-Mustang 260,Pre-World's Fair Car.
64-Fairlane500 S/C waiting for a 390-4spd.
68-Mustang 289-Sunlit Gold 80,892Mi
78-Buick LeSabre 403 4V
84 Volvo DL Wagon
Junior User
Joined: Feb 2002
Posts: 75
Likes: 0
69 F250 Wire Problems/tail lights HELP!!
Mil1ion, that's what I needed to know. I will look for it today. The PO had a valve job done on the truck before I bought it 3 weeks ago........maybe the mechanic forgot to attach the ground leads to the heads.....
Posting Guru
Joined: Jun 1999
Posts: 2,415
Likes: 3
From: Comox Valley, Canada
69 F250 Wire Problems/tail lights HELP!!
Well if you are sure no one has been working on the wiring and possibly hook them back up wrong, then I would say that the turn signal switch is doing werid things and needs to be replaced. But I would recheck to make sure no one has been moving wires around.
What happens when you turn on the left turn signal ??
Sparky
>If I use the right turn (up) the front trun signal will
>light-up (correctly) and the lfet rear will go on and blink.
>The right rear lights do work.. any suggestions
What happens when you turn on the left turn signal ??
Sparky
>If I use the right turn (up) the front trun signal will
>light-up (correctly) and the lfet rear will go on and blink.
>The right rear lights do work.. any suggestions