3rd Brake Light Not Working
Thread Starter
|
New User
Joined: Mar 2017
Posts: 2
Likes: 0
3rd Brake Light Not Working
Hey all, new to Ford trucks, new to the forum! Self-proclaimed newbie turning enthusiast! Third brake light doesn't work on my '82 F100. Rear brake lights work fine. No voltage to lamp housing. Does anyone know how I should proceed from here? Don't know much about electrical but would like to learn!🔌
Moderator
Joined: Jan 2001
Posts: 56,966
Likes: 2,728
From: Virginia
Your truck did not come with a 3rd brake light from the factory. So it was added or you are looking at the white cargo light.
For a experiment, go in and turn the headlight switch **** all the way to the left so the domelight comes on inside. Then go out and check for voltage at the light on the back of the cab.
For a experiment, go in and turn the headlight switch **** all the way to the left so the domelight comes on inside. Then go out and check for voltage at the light on the back of the cab.
Thread Starter
|
New User
Joined: Mar 2017
Posts: 2
Likes: 0
Jumping to Conclusions!
You were right, not a 3rd brake light. Why would there be a third bake light in 1982!? Wow, don't I feel dumb! It is the cargo light and it works fine when headlight **** turned all the to the left! Thanks for the experiment! Always check the simplest things first I guess!
Moderator
Joined: Jan 2001
Posts: 56,966
Likes: 2,728
From: Virginia
On my old 80 that is the only way it would come on, to manually turn the **** on the headlight switch. Not sure why they didn't just hook it up to the domelight. I think there may be a diode in the wiring somewhere to block the domelight power going to the cargo light when you open the door. But lets both come on with the switch.
Lead Driver
Joined: Feb 2013
Posts: 5,006
Likes: 72
From: Roseville, MN
I never needed the dome light on when I needed a cargo light, or needed a cargo light when I needed the dome, so on my '85 I ran a separate wire from a switch. I'm guessing Ford didn't do that because then people could turn on a white light on the back of the vehicle when it wasn't in reverse.
Thread
Thread Starter
Forum
Replies
Last Post
