Brake Light Conundrum

Good Afternoon!!

So I have searched the forum and there are quite a few lucky soles who have had brake light issues.... I now count myself as one but was not able to find my specific twist:

My brake lights ONLY work when the lights are on. I do not have "tail lights" when the lights are on, just brake lights. Brake lights DO NOT come on with the brake pedal. Turn signal works on pass. side but not drivers.

I just replaced the brake light switch as a precaution and its cheap so I know it s good. I have three wires at the switch. All harnessed together so its impossible to trace. I have two spliced together going to one terminal and one to the other. Its a simple switch and I tried both sides so I dont think it matters which terminal its on. I should get my multimeter back from a buddy soon so I can further investigate, but I know one of the wires has 12V constant - sparks proved that one out.

Is the third wire for the signals? I have an aftermarket signal switch on the column. I am thinking the signal switch might be bad/rattle loose??

 

Sounds much like mine: http://www.earlycj5.net/forums/showthread.php?109336-Another-rear-light-question
once you start with the test light it's easy.
I sliced down my harness to figure out the wires- didn't want to but did it. 3 wires- 1 is parking lights so you can jump this from one light (bottom filament of dual filament bulbs) right to other (bottom filament of right side) 2nd wire is brake/turn of left side- 3rd wire is brake/turn of right side. Mine were all mixed up plus right side was cut up front near signalstat and I had to rerun that one.

 

X2 on questions above. Will also add do you have a 4 way flasher involved and/or is it included in your T/S switch?
Be it known that the 3rd wire on your stop switch may be causing multiple problems unless it was added to bypass a previously broken (open) wire.

 

Without getting into fine detail, I would start by FiRST making VERY sure each tail-light housing is well grounded AND each socket and each contact pin is very bright/clean. Strange feedback happens when one light circuit is forced to seek a ground through the other one, via bulb filaments. Possibly such as you describe.

Also the turn signal unit would be an obvious place to inspect and rehabilitate, given your symptoms. (The "turn" and "brake" filament are the same on each side, but controlled selectively from the turn unit.)

Could well be more than one factor, so it pays to get the basics in shape, then chase the weird particulars only if they persist.

 

I've used something similar on my old hot rod to help with using a dual element single bulb per side, simplified wiring it.

http://www.carid.com/tow-ready-trai...3727566.html?gclid=CPO9yt2OoMECFWsV7AodHEQA7A

 

Thanks for all the feedback!!

The front indicator lights work properly. Tailights are grounded well and the bulbs are in good shape. I do not have 4 way flashers, just turn indicators. The brake light switch is an oem replacement, nothing custom. I put new connectors on as well to ensure no issues there.

I hope to get into the turn signal switch this weekend. As far as the comment that the third wire at the brake light switch is an issue....I think I will have to cut up the "harness" to trace it out.

In the meantime, I am going to read through the threads you have referenced and do my homework!

Matt

 

These kinds of troubles can originate in the turn signal. Normally turn signals don't go bad, they just get dirty or someone connects them wrong. If you think about it, the turn signals are the "brains" of the lighting.
They turn some on, some off, and flash others all dependent on where the switch is positioned.

It is a simple matter to take the turn signal apart. Once apart the switch is easy to see. The switch is held together by several tabs that wrap around the fiber board. Carefully bend the tabs to allow the fiber board to come loose.

As you are doing this be careful to note what parts come loose from inside the switch. There will be a triangular shaped "slider" (wiper) as well as a spring. Note how they come apart and how the slider connects inside the switch for re-assembly purposes.

I usually clean up the dielectric grease inside and then burnish all of the terminals inside the switch and the wiper with some fine grade emery cloth and get them all shiny. Re-assemble switch and the housing assembly. Re-connect and see how it works. It should then be good for the next fifty years or so. Mark it on your calendar for 50 years hence that you'll need to do this again.

If you can get 'hold of some dielectric grease you can put some of it inside the switch. Radio Shack ought to have some, if not an electrician could give you a dab of it. You don't need much,just a tiny dab.

 

As a side note, dielectric (silicone) grease is actually an insulator. The name means "non-conducting." It helps seal rubber boots etc.

On electrically conducting parts it should only be applied where the contact pressure is high enough to penetrate the grease. I imagine the Sparton contacts fall in that category.

For more delicate connections electrical connector grease, with Polyphenyl Ether, rather than silicone, is conductive and protects the contacts.

 

NorcoJeep have you got this working yet?