Wiring Problem: Running lights wired into break lights (1 Viewer)

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Jan 14, 2007
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Location
Wilkes-Barre PA
Ok here is my problem with my 1977 FJ40

1.Everytime I step on the break. My Front running lights come on, and also my license plate light comes on.
2. I dont have front turn signals.
3. My running lights dont come on when I have my headlights on.

So I know I crossed my running lights into my break lights.

I recently was doing some work on it, I took out the instrument cluster, and disconnected some switches. Everything switch has its own type of connector so there was no reason to mark anything. I moved some wires around and NOTHING!

Any help is appreciated. Thanks
-Alan-
 
You may have a "floating ground" in the rear lamps. Fix the ground to lamp housing connection and the brake light problem may go away. The rear brake and running lights share a ground and if it isn't there, current will flow through the running lights until it finds a ground.
 
I have a similar problem. All my lights work correctly except when I step on the brake my left front running light also lights up. It still works as a running light and turn signal. I will check the ground on the brake lights.
 
I had almost exactly the same issue. It was the ground wires. When the grounds no longer worked the lights would groud through the other circuit instead. The symptoms changed with each light socket I fixed. It was confusing and weird. Such as the dash turn signal indicator lighting up when I pressed the brake pedal, tail lights going off when I used the left turn signal...

Clean up all of your ground connections and see what happens.
 
Wow and I thought I had it bad. Well I am going to mess around with it in the next few days. Ill let everyone know how it turns out.
 
Ok here is my problem with my 1977 FJ40

1.Everytime I step on the break. My Front running lights come on, and also my license plate light comes on.
2. I dont have front turn signals.
3. My running lights dont come on when I have my headlights on.

So I know I crossed my running lights into my break lights.

I recently was doing some work on it, I took out the instrument cluster, and disconnected some switches. Everything switch has its own type of connector so there was no reason to mark anything. I moved some wires around and NOTHING!

Any help is appreciated. Thanks
-Alan-
does your tail light come on when you pull the light switch?
Check your tail fuse.
Another reason maybe that the tail fuse is blown (or a brake in wirng) and you have the wrong bulb in tail/brake socket.
It is just not clear, if you are saying noting is coming on when you pull the light switch or only the front lights are not coming on. If it is a case of mismatched wires the tail light will come on (which is realy the brake light) as you pull the switch.
I can't see this being a grounding problem, unless it is only doing that when the light switch is pulled which also you didn't say.
 
THAT WAS IT! I had the wrong bulb in the brake light spot!! It was shorting out. But now I dont have running lights at all. I have turn signals and flashers but no running lights on the front or back.
 

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