tail and brake lights

[Ramiro0727]

I'm installed a American Autowire Power Plus 20 harness in a 69 C10. When I went to connect the the rear light harness I made. When I connected the wires to the drivers side Tail lights. The tail light powered on and stayed on. I connected the the passenger side and the tail light was off. The only way the passenger light turns on is when I turn on the light switch. Both turn signals work properly. I still haven't added all my ground connections. Could the grounds be the problem? Also when I apply the brakes the tail lights don't do anything and the reverse lights as well.

Thanks,
Ramiro

[Ol Blue K20]

Until all the grounds are hooked up you won't know what's working or not.

[Ramiro0727]

Originally Posted by Ol Blue K20

Until all the grounds are hooked up you won't know what's working or not.

Ol Blue K20,

Ill be hooking up the grounds this afternoon.

Ramiro

[Ol Blue K20]

Originally Posted by Ramiro0727

Ol Blue K20,

Ill be hooking up the grounds this afternoon.

Ramiro

Awesome, I hope everything works!

[Ramiro0727]

Originally Posted by Ol Blue K20

Awesome, I hope everything works!

Ol Blue K20 thanks. I have installed 3 grounds so far. I started from the rear. I installed 2 ground cables from the frame towards the rear of the bed. One on each side. The next ground cable I installed was from the cab to the frame just behind the passenger door. Still having the same issues. Tomorrow I will add a few more grounds. 1 from the motor to the frame, the inner fender well to the frame and from the frame to the core support. Hope fully this takes care of the problem I’m having. Here are the ground cables I made. I used 4 gauge cable with copper lugs.

Thanks,
Ramiro

[mr48chev]

The tail lights shouldn't work at all unless the switch is turned to an on position., Either park or with headlights on.

[Ramiro0727]

Originally Posted by mr48chev

The tail lights shouldn't work at all unless the switch is turned to an on position., Either park or with headlights on.

mr48chevy, The light switch is turned off. When I made the connection on the drivers side tail light and remounted the tail light housing. The tail light automatically came on. With the light switch being off. I would turn on the light switch and the passenger tail light will come on.

Thanks,
Ramiro

[Andy4639]

Originally Posted by Ramiro0727

mr48chevy, The light switch is turned off. When I made the connection on the drivers side tail light and remounted the tail light housing. The tail light automatically came on. With the light switch being off. I would turn on the light switch and the passenger tail light will come on.

Thanks,
Ramiro

That isn't a ground issue. If it where a ground issue nothing would work ever. You need a 12v source and a ground for a light to work. Without both, no lights can work. If the lights came on without the head light switch on then something isn't wired right.

Now as far as the wiring goes the head light switches sold today are for 71-72 trucks mostly. The 67-70 if I remember right are different from the other's on how the wires hook up.


You need to trace out the Auto wiring harness and make sure you didn't cross a wire up.

[Ramiro0727]

Originally Posted by Andy4639

That isn't a ground issue. If it where a ground issue nothing would work ever. You need a 12v source and a ground for a light to work. Without both, no lights can work. If the lights came on without the head light switch on then something isn't wired right.

Now as far as the wiring goes the head light switches sold today are for 71-72 trucks mostly. The 67-70 if I remember right are different from the other's on how the wires hook up.


You need to trace out the Auto wiring harness and make sure you didn't cross a wire up.

Andy4639 I will check the switch and then trace the harness wiring. There was someone else that was getting the truck ready for my son. So now I'm stuck trying to finish it up. So I'll double check his wiring.

Thanks,
Ramiro

[Andy4639]

Originally Posted by Ramiro0727

Andy4639 I will check the switch and then trace the harness wiring. There was someone else that was getting the truck ready for my son. So now I'm stuck trying to finish it up. So I'll double check his wiring.

Thanks,
Ramiro

I can understand that. Hopefully it's a simple fix.
Here is the schematic for this type truck. It's a general one that covers all the 67-72 trucks.
You can down load it and use paint to open it and make it bigger.

[VetteVet]

you should have one wire going to the tail lights from the front connector, usually dark brown. At the rear connector this wire feeds two wires to the left and right tail light.
There will be a dark green wire to the right brake/turn light and a yellow wire to the left brake/turn light.
Trace the right tail light wire back to the rear connector and see if it goes to the brown wire and then see which wire goes to the left tail light.
Like Andy said the left tail light wire is coming from a full time hot source from the key off circuit.
Did someone wire in a trailer connector at some point?

Here is the harness for the 67 to 72 trucks. The license plate light also gets power from the brown wire.

[Ramiro0727]

Originally Posted by VetteVet

you should have one wire going to the tail lights from the front connector, usually dark brown. At the rear connector this wire feeds two wires to the left and right tail light.
There will be a dark green wire to the right brake/turn light and a yellow wire to the left brake/turn light.
Trace the right tail light wire back to the rear connector and see if it goes to the brown wire and then see which wire goes to the left tail light.
Like Andy said the left tail light wire is coming from a full time hot source from the key off circuit.
Did someone wire in a trailer connector at some point?

Here is the harness for the 67 to 72 trucks. The license plate light also gets power from the brown wire.

Attachment 2045188

VetteVet , I made my own rear light harness using the original connector. I followed the drawing for the rear lights. The previous person wiring his truck connected the wires from the harness to the original connector. I need to check if he put the right color wires to the terminal on the connector. When I redone the rear connector . I checked for continuity on each wire that went to each terminal on the connector. All brown wires were in the same terminal and so forth.

Ramiro

[Ramiro0727]

Originally Posted by VetteVet

you should have one wire going to the tail lights from the front connector, usually dark brown. At the rear connector this wire feeds two wires to the left and right tail light.
There will be a dark green wire to the right brake/turn light and a yellow wire to the left brake/turn light.
Trace the right tail light wire back to the rear connector and see if it goes to the brown wire and then see which wire goes to the left tail light.
Like Andy said the left tail light wire is coming from a full time hot source from the key off circuit.
Did someone wire in a trailer connector at some point?

Here is the harness for the 67 to 72 trucks. The license plate light also gets power from the brown wire.

Attachment 2045188

VetteVet, I traced the wiring harness under the dash. I see that the yellow wire is off the connector at the steering wheel. I put my test light in it. It has power with the key off Like Andy suggested. Everything seems right. I did notice that there is a Black wire from the steering column connector that is not grounded properly. I will purchase a ring terminal and ground it.

Thanks,
Ramiro

[Andy4639]

The black wire coming from the steering column should be the horn ground wire.

[Ramiro0727]

Originally Posted by Andy4639

The black wire coming from the steering column should be the horn ground wire.

Thanks Andy4639. Back to trying to figure this out.

Ramiro

[Ramiro0727]

Well I had 2 wires connected wrong on the rear light harness I made. Made the corrections. Now both rear lights are on. I press the brake switch and they go off. I looked at the connections from the American Autowire fuse box and every thing looks correct. I checked 3 wires on the connector that comes from the fuse box to the steering column. The white brake switch wire has constant power also. The yellow and Green tail light wires have constant power when the key is on? I cleaned the area where the tail light buckets go into the bed. To make sure I'm getting a good ground. Not sure what I need to do next.

Thanks,

Ramiro

[VetteVet]

Originally Posted by Ramiro0727

Well I had 2 wires connected wrong on the rear light harness I made. Made the corrections. Now both rear lights are on. I press the brake switch and they go off. I looked at the connections from the American Autowire fuse box and every thing looks correct. I checked 3 wires on the connector that comes from the fuse box to the steering column. The white brake switch wire has constant power also. The yellow and Green tail light wires have constant power when the key is on? I cleaned the area where the tail light buckets go into the bed. To make sure I'm getting a good ground. Not sure what I need to do next.

Thanks,

Ramiro

Here is your problem. The white wire only has power when the brake switch is depressed to turn on the brake lights. (yellow and Green wires).

The purple wire only has power when the key is on. It comes from the fuse panel turn signal flasher.

The brown wire has constant power, when the emergency flasher switch is closed it sends power to all four turn lights, the brakes and turns are the same lights in the rear and they share the yellow and green wires.

I have a diagram of the three wires and their positions in the column harness plug that I will post for you. I remember that the white wire goes on one end and the black wire goes on the other end.

Here is a picture that should help.



His left hand is the wiring plug from the fuse panel.

[Ramiro0727]

Originally Posted by VetteVet

Here is your problem. The white wire only has power when the brake switch is depressed to turn on the brake lights. (yellow and Green wires).

The purple wire only has power when the key is on. It comes from the fuse panel turn signal flasher.

The brown wire has constant power, when the emergency flasher switch is closed it sends power to all four turn lights, the brakes and turns are the same lights in the rear and they share the yellow and green wires.

I have a diagram of the three wires and their positions in the column harness plug that I will post for you. I remember that the white wire goes on one end and the black wire goes on the other end.

Here is a picture that should help.

Attachment 2046707

His left hand is the wiring plug from the fuse panel.

VetteVet,

The white wire should only have power when the brake switch is pressed? I was checking the white wire on the steering column connector. I will take a picture of the steering column connector.

Ramiro

[Ramiro0727]

Here is the picture of connectors on the steering column.

[Ramiro0727]

Well I have got the issue with the brake lights corrected. It was the brake switch. Now everything works. But when I turn on the headlight switch the turn signals don’t work in the rear. The front ones work correctly.

Thanks,
Ramiro