HELP! No Brake Lights

[Power Wagon 440X4]

I have asked this question before and it was solved with a new turn signal switch thanks to you guys.
This time its on a 85 D150 and the turn signal switch is new. the hazzard, turn signals all work as they should and the brake light switch is new.
This truck is a cruise control optioned Dodge and I am getting no power to the switch.

Please point me in the right direction to look or where can I add in direct power to make the brake lights work.

I hate Electrical Headaches! :-((

 

[Polara_500]

You're getting no power to the switch on the brake pedal?? Should be two wires at the switch, (should be a gray and a white), the gray is the hot from the fuse block (9?) and shouldn't be continuity through the switch until the brake pedal is depressed so the white should not have power. Cruise control does not go through the brake light circuitry, that's a separate switch with dark blue wires. May be a common switch, but the wiring is supposed to be independent. Good luck.

 

[Power Wagon 440X4]

Yes there is no power to the switch and the color wires you mentioned are correct. I put power to the gray wire and the brake lights come on without pressing the pedal.

 

[Polara_500]

Ok, that's weird. Make sure the switch is properly adjusted, open when pedal relaxed but makes within a short amount of pedal travel, then go check the fuses, particularly #9 I think (should be marked brakes).

 

[Power Wagon 440X4]

There is no fuse area that says brakes just external lights.
All fuses are good, and the ones that were questionable has been replaced.
Whats weird is everything else works except the Brake lights.
The switch is adjusted properly and closes when the pedal isn't being pressed,
and open when pedal is pressed.

 

[7mopar]

Ohm and volt meter time. Things to check with that meter.
Brake light switch, turn signal switch, brake light sockets and grounds.

You're getting no power to the switch on the brake pedal?? Should be two wires at the switch, (should be a gray and a white), the gray is the hot from the fuse block (9?) and shouldn't be continuity through the switch until the brake pedal is depressed so the white should not have power. Cruise control does not go through the brake light circuitry, that's a separate switch with dark blue wires. May be a common switch, but the wiring is supposed to be independent. Good luck.

That depends upon the year of truck. My 82 with 83 body wiring the cruise cut off and brake light switch is one. Believe it has four wires.

 

[Power Wagon 440X4]

This is a 85 with cruise, there are 2 seperate plugs.
one plug has the gray and white wire as Polara mentioned.
Then there is a another plug with 4 or 5 wires going into the switch box.
The plug that with the gray and white wires has no power going to it.
I assume the other one is for the cruise.

Could a bad ground at the column cause this?
all the other lights opperated by the column work.

 

[Polara_500]

Your brake light switch should be open and close when pressed.

 

[Polara_500]

I was working out of an 83 s/m, can't find the 84 right now, don't have an 85, will go look at the 86 book.

 

[65 sporty]

The switch is adjusted properly and closes when the pedal isn't being pressed,
and open when pedal is pressed.

The switch should be open when it's pressed and closed when the pedal is pushed

 

[Power Wagon 440X4]

I would think the 84 would be closer comparison,
because some of the plugs changed in 86
like the one going from the engine harness to the tail lights.
Still wouldn't hurt to take a look and I appreciate the effort.

 

[Power Wagon 440X4]

The switch should be open when it's pressed and closed when the pedal is pushed

That's what it is doing, but there is no power going to the switch.

 

[65 sporty]

You said if you put power on the gray wire the brake lights light up, they shouldn't light until the pedal is pressed and the switch closes. If you put power on the gray wire and you have power coming out on the white wire with the pedal up the switch is bad. You still need to find out why you don't have power on the gray wire.

 

[7mopar]

Fuse to brake switch to turn signal switch if memory is correct. It appears the problem stops at the turn signal switch if all other lights work.
Had the same problem last winter. Ended up cleaning the turn signal switch contacts and applied new jell. All is now ok.

 

[Power Wagon 440X4]

Fuse to brake switch to turn signal switch if memory is correct. It appears the problem stops at the turn signal switch if all other lights work.
Had the same problem last winter. Ended up cleaning the turn signal switch contacts and applied new jell. All is now ok.

Thats the same problem I had in another truck and got the help from here suggesting it was the turn signal switch. Installed a new TS switch and the brake light worked.

This truck started out with weak flasher lights but had brake lights.
Installed a new turn signal switch and the flashers were bright again but the brake lights stopped working.
Took that switch out and put another one in and still no brake lights.

Put power directly to the gray wire and the brake lights come on without pressing the pedal.
The problem has to be somewhere else.

On the first truck I had power to the brake light switch but no brake lights.
TS Switch fixed that.
This truck has nothing coming into the brake light switch.

Another thing is when I started this problem search both tail lights were burned out.
Replaced the bulbs and the other things mentioned and it hasn't burned out the bulbs or blown a fuse.

 

[Polara_500]

As said the power comes from the fuse block to the brake switch, (normally open contacts), then through the turn signal switch, (normally closed with no t/s on), to the brake lamps. Troubleshoot the problem instead of patching or creating a wiring monster by wiring around the problem. I checked the 86 book and the only thing that changed is they now show a composite switch at the brake pedal with both the stop lights and the cruise using 3 different sets of contacts on the one switch.

 

[Power Wagon 440X4]

I dont want to create a "Wiring Monster". I believe in fixing it right and always have. The reason for a temporary fix is to use the truck until the problem is solved. There are 3 separate plugs. the 2 as mentioned before going to the brake switch and a small separate plug with 2 wires blue and light blue or white. a different column was put into this truck before I got it. But it all worked correctly untill recently. Why didnt the TS switch fix the problem as before? and power from the fuse block is getting to the TS switch because the TS and hazzards work. same problem with 2 different TS switches. One factory one that I know worked before from another truck and the brand new one that is in it now.

 

[Polara_500]

Okay, I wasn't implying anything, but from personal experience it's real easy to jerry-rig a temporary fix, and once it's working then totally forget about it until it quits again 4 years from now and I have to go back and figure out what I did and why I didn't do it right the first time, all after I've finally figured out the original problem.

Now for the stop/turn signal issue - the stop light power goes THROUGH the turn signal switch, it does not power the turn signals. This allows the turn signal switch to interrupt the stop light to let the turn signal blink the correct lamp. While I believe both come from the same fuse, they come from different wires from a large splice downstream from the fuse. So yes, there's commonality, but a lack of power to the brake light switch does not mean there can't be power to the turn signals.

 

[Power Wagon 440X4]

I understand your point Polara. I cant understand how 2 turn signal switches could be bad. This is very frustrating! I can build a vehicle from bumper to bumper but absolutly hate electrical problems.

 

[Polara_500]

Try this.
The fuse box pdf shows the fuse box side of the cab wiring diagram, the Inst panel shows the turn signal, and the cruise one shows the changes to add cruise control.

If you look at the t/s switch, the white brings the stop light power thru the switch allowing it to be interrupted so the t/s can be seen when activated. The red brings in power from the t/s flasher, and the dark blue brings in power from the hazard flasher. Three different power feeds to/through the t/s switch.

You're not getting power to the stop light switch, find and fix that first. If you follow the gray wire back to the fuse panel from the stop light switch you'll see the splice I mentioned - possible issue?

I fudged this one up for you, the red shows the power from the fuse box to the stop light switch, and when depressed it goes through that switch out the white and from there via the t/s switch to the stop lamps.