brake light switch problem...

[grdprx]

I'm working on my brake lights / turn signals.  Going down a check list I found, you need 12v from the pink wire to the switch, then you need 12v from the other side when you press the switch.  I have the opposite, 12v when not pressed, 0 when pressed.  Now, the screwy thing is No brake lights ever...     Is the switch bad then?

I have a new signal cam, but must be having contact problems behind the steering wheel.  I'm really not in the mood to deal with electrical this year...

BTW, 68 as in my Avatar.

[nascarxx29]

Pink is the feed from the fuse box the white is the device the turn signal switch.You need power on both sides

[grdprx]

Pink is the feed from the fuse box the white is the device the turn signal switch.You need power on both sides

Right, but from what I understand; power is active when the switch is pressed.  Mine is running opposite, I have 12v when not pressed; no voltage when the switch is pressed.

Or is that right, and I'm not comprehending it properly in my brain?

[doctor4766]

Nah that can't be right.
Sounds like you have a normally closed switch in there and not a normally open switch.

[terrible one]

I may be mistaken but that's right, isn't it? When the brake pedal isn't pressed the switch is pressed/ held closed, thus 0v and no brake lights. Then when you press the pedal the switch is allowed to spring open and you gt 12v and brake lights. Just like the door jamb switches, right?

[Nacho-RT74]

yes just like door jam switches. Pink wire to it is hot, and white is hot just when switch is released.

then white runs to column switch on 70 and lates, on earliers runs to hazzard switch first and spliced from there to column switch as far I remember.

and being analized the 69 and earlier cars diagrams, you can press brakes with hazzards on and brakes will light on "bypassing" hazzards, opossite than laters where with hazzards on, brakes won't come up

[grdprx]

I may be mistaken but that's right, isn't it? When the brake pedal isn't pressed the switch is pressed/ held closed, thus 0v and no brake lights. Then when you press the pedal the switch is allowed to spring open and you gt 12v and brake lights. Just like the door jamb switches, right?

Your probably right, I'm all turned around sitting upside down under the dash!     I'm having a problem with the dog leg on the pedal making contact with the switch, so that's adding to my problem.  I'll have to get back under there tonight and hash it out.

So, on my 68, your saying follow the white wire to the hazzard switch Nacho?  Then it runs up to the turn signal cam.

[doctor4766]

I may be mistaken but that's right, isn't it? When the brake pedal isn't pressed the switch is pressed/ held closed, thus 0v and no brake lights. Then when you press the pedal the switch is allowed to spring open and you gt 12v and brake lights. Just like the door jamb switches, right?

Ah yeah of course.
I'll blame my friend Johnny Walker on that brainfart.

[Nacho-RT74]

So, on my 68, your saying follow the white wire to the hazzard switch Nacho?  Then it runs up to the turn signal cam.

let me check diagrams and will reply on that

[Nacho-RT74]

Ok... the white wire DUNNO WHY gets spliced at turning switch plug and runs from there also to hazzards plug. That doesn't mean the signal gets INTO the switch and then runs to hazzard switch, just that how the wire is running, but signal reachs at the same time to both... now... WHY ? not really sure. My only clue is to feed stop light even with hazzards on, opposite than laters

[grdprx]

Thank you very much Sir Nacho, the electrical wizard!  Who knows what they were thinking 40 years ago...

I'll follow the trail, see if it leads me to my issue. 
To be continued...

[Nacho-RT74]

My only clue is to feed stop light even with hazzards on, opposite than laters

this could be confirmed by any pre 70 model owner. tunr on your hazzards and press brakes to check if this statement is true.

grdprx... there is a fact and the FIRST you need to get is 12 volts at pink wire even unplugged from brake light switch... then will check the rest

on diagram, the pink wire looks to be spliced from hazzard flasher input signal, what of course should get also 12 volts always.

[grdprx]

I have brake lights!!!   I checked for voltage at various stages on the white wire.  Had it all the way up to the turn signal cam.  Checked the green wire, no V..  Yes on the brown wire though. Green wire didn't have any breaks in it, carried continuity from the connector to the cam.

So, I checked the movement and operation of the cam and switch on the column.  I had replaced the cam last year, and I discovered today that it wasn't making contact with the green wire contact point.  I bent the metal arm on the back on the cam, voilà!  Green wire carries voltage now!  I have 3 out of 4 brake lights working!  Batting .750 works for me.  Tail light works on that bulb, and I'm pretty sure they are all new bulbs...  But that's a minor issue to deal with.  I'm literally jumping for joy!  Thanks guys for your help!