1977 cordoba Brake lights no worky

[crmzendrgone]

Well, it has been a very long time since I have been on here. So long that my son who was a wee boy has now grown and bought himself a 1977 cordoba just like mine (some differences).
So just realized the brakes lights are not working. All bulbs are good believe the switch is good. But what I am hoping for is someone can point me in the direction of a wiring diagram for the brake lights/ tail lights.
The switch has a pink and white connected with two blue at the rear of the switch. I am confused how the actual brake light get powered. I physically took the bulb touched the two bottom contacts to the negative battery terminal each separately and touched the cup to wire connected to positive. one filament for the park/ turn signal lit and the brake filament lit. So where is the positive for the actual circuit to light the brake filament.
Anyway any info or wiring diagram helps. Thank you, thank you


P.S. photo post soon.

 

[PurpleBeeper]

I don’t have the wiring diagrams, but the brake switch has direct power from the battery (always hot). The “outbound” wired go to the brake lights & your cruise control.
So….see if you have 12volts at all times going at the brake switch. Push the brake pedal down and see if you have 12 volts coming out of the brake switch

 

[pnora]

Do both turn signals work in the rear? If so that means the bulbs, wires, and grounds are good from the steering column turn signal switch to the rear of the car. Now you need to test the brake light switch. It there 12 volts on the pink? If no check the fuses. If yes depress the pedal and see if there is power on the white. If no power replace the brake switch. If yes your problem is most likely the turn signal switch.

 

[Don Frelier]

Your bulb test was backwards (polarity reversed).
The outer metal shell of the light bulb is negative.
The two soldered posts on the bulb are each running light and brake light.
Since it's just a filament the bulb will light with polarity swapped which is what you did.
But it's not how they function in the car.

 

[crmzendrgone]

I don’t have the wiring diagrams, but the brake switch has direct power from the battery (always hot). The “outbound” wired go to the brake lights & your cruise control.
So….see if you have 12volts at all times going at not the brake switch. Push the brake pedal down and see if you have 12 volts coming out of the brake switch

Thank you.

 

[crmzendrgone]

Do both turn signals work in the rear? If so that means the bulbs, wires, and grounds are good from the steering column turn signal switch to the rear of the car. Now you need to test the brake light switch. It there 12 volts on the pink? If no check the fuses. If yes depress the pedal and see if there is power on the white. If no power replace the brake switch. If yes your problem is most likely the turn signal switch.

Sorry, yes park lights work and turn signals work as well as flashers.
Ok, great, I was needing to know what the colors are (pos, Neg) I will test and reply. I think I tested those ( will do again.) but did not get any voltage at the pink or white with pedal depressed or not.

 

[crmzendrgone]

Your bulb test was backwards (polarity reversed).
The outer metal shell of the light bulb is negative.
The two soldered posts on the bulb are each running light and brake light.
Since it's just a filament the bulb will light with polarity swapped which is what you did.
But it's not how they function in the car.

I thought that but I did it the opposite way too. But that explains why I was lost with all the grounds at the tail lights.

 

[crmzendrgone]

So, now that I am awake and can think better during the day. This was my process.
I took my test light connected to bat. pos. probed the 5 wires going to the taillights. black, purple, green, brown and white. They all showed as ground (test light lite).
Then turned key on, lights on found that the black that makes contact with one of the soldered posts (with voltmeter touching soldered post and black of meter touching body ground) had pos. 12.6v the green was 0.0 (with same voltmeter connection as before) until the turn signal was turned on then got fluctuating pos. voltages on the green. The housing(?) that holds the bulb that makes contact via the ring which has white connected to it was neg./ ground no volts.
I know I tested the brake switch connectors but maybe didn't get good contact will test again with new information.
So that I know, there is a pink and white wire connected to the brake switch as well as 2 blues at the rear of the switch, am I to concern myself with the blue wires?
I will get pictures tonight after work.
Again, THANK YOU, THANK YOU for the help.

 

[pnora]

So, now that I am awake and can think better during the day. This was my process.
I took my test light connected to bat. pos. probed the 5 wires going to the taillights. black, purple, green, brown and white. They all showed as ground (test light lite).
Then turned key on, lights on found that the black that makes contact with one of the soldered posts (with voltmeter touching soldered post and black of meter touching body ground) had pos. 12.6v the green was 0.0 (with same voltmeter connection as before) until the turn signal was turned on then got fluctuating pos. voltages on the green. The housing(?) that holds the bulb that makes contact via the ring which has white connected to it was neg./ ground no volts.
I know I tested the brake switch connectors but maybe didn't get good contact will test again with new information.
So that I know, there is a pink and white wire connected to the brake switch as well as 2 blues at the rear of the switch, am I to concern myself with the blue wires?
I will get pictures tonight after work.
Again, THANK YOU, THANK YOU for the help.

You make my head hurt. Follow the simple word for word way to diagnose in reply #3

 

[crmzendrgone]

You make my head hurt. Follow the simple word for word way to diagnose in reply #3

I make my own head hurt. That’s what was confusing me and that’s why I posted what I did to clarify why I’m confused. Where is positive coming to the bulbs for the park lights and the brake lights. But I will follow.

 

[pnora]

I make my own head hurt. That’s what was confusing me and that’s why I posted what I did to clarify why I’m confused. Where is positive coming to the bulbs for the park lights and the brake lights. But I will follow.

First of all forget park lights they are not relevant at this time or on the same circuit. So get a 12 volt test light and see if there is power 12 volts at the pink wire. We will do this one step at a time.

 

[crmzendrgone]

First of all forget park lights they are not relevant at this time or on the same circuit. So get a 12 volt test light and see if there is power 12 volts at the pink wire. We will do this one step at a time.

Sounds good to me. I’ll have the answer once I get home from work. Thank you for your help. I hope I’m not coming off as (whatever) just hard for me to explain sometimes what I’m doing.

 

[crmzendrgone]

Test light. Connected. Working. Punctured pink wire. No light. Key off and out (Pretty sure that doesn’t matter). Next step please. Thank you.

 

[72RoadrunnerGTX]

Now go to the fuse box with your test light and verify power is present at both ends of the “Brake” fuse. Never mind the blue wires at brake light switch, they are for the cruise control cancel.

 

[pnora]

Test all the fuses with a test light or voltmeter. Also make sure the fuse is in there. Do not look at them and say they look ok. You need power on the pink.

 

[crmzendrgone]

Test all the fuses with a test light or voltmeter. Also make sure the fuse is in there. Do not look at them and say they look ok. You need power on the pink.

Ok. I figured I would test fuse panel with the key on and test light connected to bat. neg. and touched both sides of all 10 glass fuses under the dash and the test light lite on all except slot labeled 1.
I also figured I would be proactive and used voltmeter touching both sides of the glass fuses and got zero volts. Then touched red to each side while black to test light and then got 12.6 on all except slot 1.
I am confused.

 

[pnora]

Ok. I figured I would test fuse panel with the key on and test light connected to bat. neg. and touched both sides of all 10 glass fuses under the dash and the test light lite on all except slot labeled 1.
I also figured I would be proactive and used voltmeter touching both sides of the glass fuses and got zero volts. Then touched red to each side while black to test light and then got 12.6 on all except slot 1.
I am confused.

So on slot 1 you had no reading on either side of the fuse? Your volt meter should be black to ground and red to the desired source you are testing. The test light is not used or needed when doing these tests. What does slot 1 say for the fuse application? Is there anything else that does not work on the car? Dome light? 4 way flashers?

 

[crmzendrgone]

So on slot 1 you had no reading on either side of the fuse? Your volt meter should be black to ground and red to the desired source you are testing. The test light is not used or needed when doing these tests. What does slot 1 say for the fuse application? Is there anything else that does not work on the car? Dome light? 4 way flashers?

I was using the test light as a known good ground. I'll check if anything else is inop. The 4 way flashers do work. My son has been working a lot as well as I have. I will have more info hopefully tonight.

 

[pnora]

I was using the test light as a known good ground. I'll check if anything else is inop. The 4 way flashers do work. My son has been working a lot as well as I have. I will have more info hopefully tonight.

You can still use a test light. Make sure you have a good ground on the clamping end and use the needle probe tip and check both ends of each fuse. Also recheck that pink wire at the brake light switch.

 

[crmzendrgone]

You can still use a test light. Make sure you have a good ground on the clamping end and use the needle probe tip and check both ends of each fuse. Also recheck that pink wire at the brake light switch.

Ok. According to the owner’s manual see pic. Which doesn’t make sense because all that works. Will attempt to take video and post link.