66 C10 Steering Column Harness

[Afirehawk1]

also working on the column harness using the American Auto Wiring Classic Update. My harness mimics the 63 with the exception of the tan/green, mine is black. do i follow the 63 or 66 wiring diagram.?

[The Rocknrod]

Just FYI, we have an electrical section if youd like me to move this thread threre I will - http://67-72chevytrucks.com/vboard/f...splay.php?f=64

[Afirehawk1]

Originally Posted by The Rocknrod

Just FYI, we have an electrical section if youd like me to move this thread threre I will - http://67-72chevytrucks.com/vboard/f...splay.php?f=64

Please
If that works best

[Afirehawk1]

Originally Posted by Afirehawk1

Please
If that works best

Any help out there?

[VetteVet]

Originally Posted by Afirehawk1

also working on the column harness using the American Auto Wiring Classic Update. My harness mimics the 63 with the exception of the tan/green, mine is black. do i follow the 63 or 66 wiring diagram.?

The wiring colors are not important, what is important is where they go in conjunction with the AA harness, which as you can see are the same for both years and the color codes follow the GM colors right on up to the late 70s years.

If you notice, the 63 colors (top right) are different than the 66 colors ( bottom right). So you are saying that you have a 66 truck with a 63 turn signal harness?
If you notice, the colors in the 63 TS harness don't match the 66 colors but the 66 colors match the AA harness. I would guess that the 63 wires feed the same lights as the 66, but you need to be sure.

The black wire in question is used to ground the horn relay so it should be connected to the horn button on the TS switch. In the 63 the tan/green wire would perform that function. To test it you could use a test light connected to the tan/green wire and ground and press the horn button and the light should light. But you said you have a black wire and the other wires match the 63 TS switch wires. I'm trying to sort this out and can't figure out which TS switch harness you actually have.

The best thing you can do test all the wires in Your TS harness and make sure they feed the wires in the AA harness. A multimeter would be very helpful for this and would be a great tool for electrical work. They are not expensive and you can get one at Harbor Freight for less than ten bucks.

The breakdown on the wires goes like this, starting from the top on the AA harness for both years.


P. white- brake lights from brake light switch.
N. dark green- right turn signal.
M. yellow-left turn signal.
L. purple- power for the turn signal switch from the fuse panel and the flasher.
K. brown-power for the turn signal switch for the emergency lights. This is blank since you don't have that function.
J. dark blue for the right front turn signal light.
H. light blue for the left front turn signal light.
G. black for the horn relay, grounded by the horn button.





Now lets look at the original turn signal switch wires, you say that yours matches the 63, top TS harness,

You have white on top. Then purple at N. which doesn't match. Then pink at M which doesn't match. Then yellow at L which doesn't match. Then the rest of them match except the tan/green.
So the questions are- is the yellow wire(L) the power wire for the TS switch lights?, and is the pink and purple wires the left and right turn light wires?

I'd like to assume that the wire functions match even though the colors don't but we need to be sure so lets test the turn signal switch you have and see if they do, even tho the colors don't.

Starting at the top with test light or multimeter on ohms scale.
white (brakes) touch white (P), to (N)purple, light should light or zero ohms on MM.
White to (M)pink, light should light or zero ohms on MM. N and M are your brake light wires. they also feed the turn signal lights.

now check the L (yellow assume power wire) to N (purple) and place the TS lever in right turn, the light should light or zero ohms on MM.

now check the L (yellow power) to M (pink) and place the lever to left turn, the light should light or zero ohms on MM.

Now continue with the rest of the wires

Yellow L to J for right turn and place the lever in right turn, light should light or zero ohms on MM. This would be the right front light turn light.

Yellow L to H, light blue for front left turn signal, light should light or zero ohms on MM.

Now we check the ground wire for the horn.

touch the test light on the G pin and to the ground plate on the column where the TS switch mounts. you should not see a light or MM reading until you press the horn button which connects the black/tan/green wire and then the light should light or zero ohms on the MM.

If you get all these readings then the turn signal switch is good and the functions match. You should be able to plug the harness into the AA harness and do a power on check of the lights and horn.


I believe I have all these right but in case you don't get all of them like I described, post back and we'll get it sorted.

[Afirehawk1]

Originally Posted by VetteVet

The wiring colors are not important, what is important is where they go in conjunction with the AA harness, which as you can see are the same for both years and the color codes follow the GM colors right on up to the late 70s years.

If you notice, the 63 colors (top right) are different than the 66 colors ( bottom right). So you are saying that you have a 66 truck with a 63 turn signal harness?
If you notice, the colors in the 63 TS harness don't match the 66 colors but the 66 colors match the AA harness. I would guess that the 63 wires feed the same lights as the 66, but you need to be sure.

The black wire in question is used to ground the horn relay so it should be connected to the horn button on the TS switch. In the 63 the tan/green wire would perform that function. To test it you could use a test light connected to the tan/green wire and ground and press the horn button and the light should light. But you said you have a black wire and the other wires match the 63 TS switch wires. I'm trying to sort this out and can't figure out which TS switch harness you actually have.

The best thing you can do test all the wires in Your TS harness and make sure they feed the wires in the AA harness. A multimeter would be very helpful for this and would be a great tool for electrical work. They are not expensive and you can get one at Harbor Freight for less than ten bucks.

The breakdown on the wires goes like this, starting from the top on the AA harness for both years.


P. white- brake lights from brake light switch.
N. dark green- right turn signal.
M. yellow-left turn signal.
L. purple- power for the turn signal switch from the fuse panel and the flasher.
K. brown-power for the turn signal switch for the emergency lights. This is blank since you don't have that function.
J. dark blue for the right front turn signal light.
H. light blue for the left front turn signal light.
G. black for the horn relay, grounded by the horn button.





Now lets look at the original turn signal switch wires, you say that yours matches the 63, top TS harness,

You have white on top. Then purple at N. which doesn't match. Then pink at M which doesn't match. Then yellow at L which doesn't match. Then the rest of them match except the tan/green.
So the questions are- is the yellow wire(L) the power wire for the TS switch lights?, and is the pink and purple wires the left and right turn light wires?

I'd like to assume that the wire functions match even though the colors don't but we need to be sure so lets test the turn signal switch you have and see if they do, even tho the colors don't.

Starting at the top with test light or multimeter on ohms scale.
white (brakes) touch white (P), to (N)purple, light should light or zero ohms on MM.
White to (M)pink, light should light or zero ohms on MM. N and M are your brake light wires. they also feed the turn signal lights.

now check the L (yellow assume power wire) to N (purple) and place the TS lever in right turn, the light should light or zero ohms on MM.

now check the L (yellow power) to M (pink) and place the lever to left turn, the light should light or zero ohms on MM.

Now continue with the rest of the wires

Yellow L to J for right turn and place the lever in right turn, light should light or zero ohms on MM. This would be the right front light turn light.

Yellow L to H, light blue for front left turn signal, light should light or zero ohms on MM.

Now we check the ground wire for the horn.

touch the test light on the G pin and to the ground plate on the column where the TS switch mounts. you should not see a light or MM reading until you press the horn button which connects the black/tan/green wire and then the light should light or zero ohms on the MM.

If you get all these readings then the turn signal switch is good and the functions match. You should be able to plug the harness into the AA harness and do a power on check of the lights and horn.


I believe I have all these right but in case you don't get all of them like I described, post back and we'll get it sorted.

I have a 66 truck with the AA specific wire setup.
I had someone rebuild me a column to convert from 2 spd to 3spd.
The harness that is in the column mimics the 63 except mine has a black wire and not the tan/green

So i want to make sure the wires are in the correct order

There is also a grey wire which I believe is the indicator light.
i was going to connect to another grey wire for lights

[Afirehawk1]

Originally Posted by Afirehawk1

I have a 66 truck with the AA specific wire setup.
I had someone rebuild me a column to convert from 2 spd to 3spd.
The harness that is in the column mimics the 63 except mine has a black wire and not the tan/green

So i want to make sure the wires are in the correct order

There is also a grey wire which I believe is the indicator light.
i was going to connect to another grey wire for lights

Getting back to this. Yes 63 column in my 66
I ordered a new 63 TS switch; AAC # 0898197US

TS Wire colors are:

White - brake switch.
Purple. This should connect to Dk Green harness which is RH rear light
Yellow. This should connect to Purple harness which is TS power.
Orange - this one is the odd color that doesn't match harness; does this connect to Yellow harness which would be LH rear light.
Dk blue- front light
Lt blue - front light

Black is horn
Grey is light

[VetteVet]

Originally Posted by Afirehawk1

Getting back to this. Yes 63 column in my 66
I ordered a new 63 TS switch; AAC # 0898197US

TS Wire colors are:

White - brake switch.
Purple. This should connect to Dk Green harness which is RH rear light
Yellow. This should connect to Purple harness which is TS power.
Orange - this one is the odd color that doesn't match harness; does this connect to Yellow harness which would be LH rear light.
Dk blue- front light
Lt blue - front light

Black is horn
Grey is light

This is getting to my point that the colors are not as important as where they go. If you have a multi-meter you can sort it out easily.

Start with the white wire connection on the TS switch only.

Measure white to all wires and two of them should read zero ohms with the TS switch in neutral. These will be the rear turn lights and brake lights (same wires). These are dark green and yellow in the later years. Your orange wire may be one of them.

Using the voltage selection on the multi-meter, test the truck harness for 12 volts power on the wires in the connector.
You should see power on two of them plus the white wire if the brake switch is depressed. Provided the harness is connected correctly.

The purple wire is TS power on later years, while a brown wire is hazard power. If you show power on that wire in the Harness, and you have hazards in your TS switch. If it is an orange in the harness then that may be the hazard wire.

It makes a difference whether the key is on or not so here is how to test.

Key off- no power on the turn signal power wire. usually purple.

12 volts on the hazard wire- usually brown or orange in your case.

12 volts on the white, brake light switch wire with switch depressed.

KEY ON- 12 volts on three wires in the harness providing the brake switch is depressed. The one without power in the previous test (purple) should be the TS switch power for the flashing lights. I would think that the harness will have a hazard wire for power but it may not if it's made specific to your application.

Let's check the 63 turn switch.

The first test I mentioned should determine the left and right rear brake/turn wires. Document those two wires. Remember we are only testing the wires in the TS switch not the harness wires.

Purple. This should connect to Dk Green harness which is RH rear light

Your post says that The purple TS wire connects to the Dk Green wire in the harness. This is normally the right rear turn/brake light wire. Refer to the white wire continuity test for zero ohms in the very first test to determine which wire is a turn /brake light wire. If you don't have a dark green wire in the TS switch you may be right.

Yellow. This should connect to Purple harness which is TS power.


Again the first test will dictate which two wires are the brake/turn wires. The normal yellow wire in the TS switch is for the LH rear turn light. Yours may be different.

Orange - this one is the odd color that doesn't match harness; does this connect to Yellow harness which would be LH rear light.


what does it match up to when you plug in the harness.?


Here is another check to find which wire is the power wire in the TS switch.

No voltage power and harness unplugged.

If the yellow is the power wire Place the TS lever in right turn and measure zero ohms between--all the wires and the dark blue(right front turn)

You should get continuity between that wire and the TS power wire and the right rear turn wire. You say it's the purple TS wire and the yellow TS power wire which connects to purple in the harness.

Now place the TS lever in left turn and measure continuity between the light blue wire( left turn front) and all the other wires.

You should get zero ohms between it and the TS power wire (you say yellow) and the left turn rear light wire, which you say is maybe the orange wire. Normally this is a yellow wire in the later TS switches.



This all may be very confusing but if you follow the tests and keep track of the color of the wires in each test you should be able to sort out the right wires to get the switch to work.