Wiring turn signal question, purple wires

[Peepaw]

Well, it wont allow to me upload pics of the wiring schematic. I was simply trying to show the difference in the wiring schematic, and when you are able to zoom in and see small differences (which I was not able to do until I got a new laptop...I am now able to zoom in and I had some wires I THINK in wrong locations)
However, that would not explain why one day everything worked and now I am having problems. Either way, I am going to go test my theory and will report back.

[pjmoreland]

Post a photo of the wires connected to your U shaped connector.

[Peepaw]

Originally Posted by pjmoreland

Post a photo of the wires connected to your U shaped connector.

Give me a few minutes and I will.


Good thing Im pig headed as Im not accepting defeat. LOL

Just when I THINK I have it figured out, I fix one thing only for a different problem to pop up.

[Peepaw]

U shaped connector under steering column.

[Peepaw]

Current situation:


Turn signals work. Brake lights work. Taillights work. Head lights work.
Left turn signal works with brakes on (right side gets bright) and left tuen stays blinking.

HOWEVER, when turn right turn signal on with brakes, my left rear brake light does not get bright.

[pjmoreland]

Your U wires are in the same order as in this spare harness I have. So you were able to fix the issue with the front turn signals?

[Peepaw]

Originally Posted by pjmoreland

Your U wires are in the same order as in this spare harness I have. So you were able to fix the issue with the front turn signals?

Yes, front turn signals work in current situation, but they do NOT illuminate when turn parking light on or head lights.

But they no longer get BRIGHT when turn lights on, and they do not come on when hit brake pedal.


So, front turn signal lamps do NOT come on when lights are turned on and everything else works except:

The left rear brake light does not light up when I have the right turn signal on. Brake light works when have lights on, or lights off (as does right side).
left rear brake light ONLY does not work when have brake pedal pushed in and right turn signal on.

[pjmoreland]

Whenever I hear about problems where the turn signals work, but the brake lights don't in certain scenarios, I suspect the turn signal switch, since it reroutes the brake signals depending on the position of the turn signal switch. I had a problem where a gummed up turn signal switch made my brake lights not work at all due to varnish on the contacts. Did you try moving the turn signal lever around a little bit to see of your left brake light will come on when the right turn signal is on?

[Peepaw]

Originally Posted by pjmoreland

Whenever I hear about problems where the turn signals work, but the brake lights don't in certain scenarios, I suspect the turn signal switch, since it reroutes the brake signals depending on the position of the turn signal switch. I had a problem where a gummed up turn signal switch made my brake lights not work at all due to varnish on the contacts. Did you try moving the turn signal lever around a little bit to see of your left brake light will come on when the right turn signal is on?

Yes sir I did that, no dice.

But I am thinking of the same thing, turn signal switch.

But, I am still at it.

I would really love it if someone could chime in about the wiring for the "U" shaped connector under the steering column.
Thats really the only wiring I do not have a clear grasp of on what goes where.
The head light switch, only question I have there is, the green wire....with lights and everything turned off, it is a clear ground (my test light beeps and gives me a green light showing it is grounded). When I turn head lights on, it goes hot. But, where EXACTLY does the green wire from head light switch go, AND is it grounded with lights/key off, or should be hot all times, or?????

[Peepaw]

That is green wire I am referring to. I know it goes to fuse box. But with lights off and key off, it is grounded. When turn key on, it goes hot (or if turn lights on). Is it hot all times, or key on hot?

[pjmoreland]

This came with an aftermarket turn signal switch I had in my truck for a few months. It has the wire functions listed.

[Peepaw]

Originally Posted by pjmoreland

This came with an aftermarket turn signal switch I had in my truck for a few months. It has the wire functions listed.

Awesome.
I will take a look and see if these match up.

I also went ahead and ordered a new turn signal switch.

I'll post back later once I match it up.

[pjmoreland]

You might be able to just clean the contacts in your current turn signal switch

[Hunter757]

This might help you if you don't have the link yet.

POST- #1 and #2 there is a link to expand the size and let you zoom in. Looks like the green goes to the fuse panel.


In my truck I have found that auto and stick shift trucks have some other color wires here and there but follow the paths and you should come up with where they go and what they do.



http://67-72chevytrucks.com/vboard/s...d.php?t=185856

[BigBird05]

The dark green wire at the head light switch (cir #44 ) should be the + feed for the dash light fuse ( gray # 8 wire ). Should only be hot with the head light switch on. Turn signal connector under the dash. Dk blue#15A goes thru the bulk head connector to a splice then on to the right front park turn signal and the right side marker. ( turns into a black wire at the splice ) Dk Blue #15B goes to the cluster plug. Lt Blue #14A goes thru the bulk head connector to a splice then on to the left front park turn signal and the left front side marker. Also turns into a black at this splice ) Lt Blue # 14B goes to the cluster plug.

[BigBird05]

The ign switch pigtail in your truck doesn't have the Dk green wire for the temp light cir. bulb check. I am guessing you have a gauge. The aftermarket pigtail does.

[Peepaw]

Originally Posted by BigBird05

The ign switch pigtail in your truck doesn't have the Dk green wire for the temp light cir. bulb check. I am guessing you have a gauge. The aftermarket pigtail does.

That is correct, I do have the gauge.

I am calling it a day today and will get back at it this week and keep yall updated. I know its something simple and Im just over looking it right now.


Thanks again everyone for yalls help

[Peepaw]

Originally Posted by BigBird05

The dark green wire at the head light switch (cir #44 ) should be the + feed for the dash light fuse ( gray # 8 wire ). Should only be hot with the head light switch on. .

Do you know if it is grounded with headlights off? Right now, I have it going to fuse box but with everything off, it is grounded. As soon as I turn headlight on, it goes hot. I just know that some times, if something is grounded, then it goes hot, it reacts differently then if it is NOT grounded, then goes hot.

I am curious to know if it is supposed to be grounded when everything is off? Because if its NOT supposed to be grounded, that might be my problem.

[Peepaw]

Originally Posted by Hunter757

This might help you if you don't have the link yet.

POST- #1 and #2 there is a link to expand the size and let you zoom in. Looks like the green goes to the fuse panel.


In my truck I have found that auto and stick shift trucks have some other color wires here and there but follow the paths and you should come up with where they go and what they do.



http://67-72chevytrucks.com/vboard/s...d.php?t=185856

Yes sir, Im finally on a computer that zooms in. LOL!

What I was curious about it, is hot all the time? Or only when key or headlight switch on?

[Peepaw]

Originally Posted by pjmoreland

You might be able to just clean the contacts in your current turn signal switch

Roger that.

[pjmoreland]

If you own a steering wheel puller, pull your steering wheel and then pop the top plastic portion of your turn signal switch off to see if the contacts are dirty. They might just need to be cleaned.

[Peepaw]

Originally Posted by pjmoreland

If you own a steering wheel puller, pull your steering wheel and then pop the top plastic portion of your turn signal switch off to see if the contacts are dirty. They might just need to be cleaned.

Roger that. Im pretty sure thats what we are going to find. I have isolated every wire. Ran ohm test on every wire from light switch to each light source and from “u” shaped connector to ignition switch, light, etc...
No breaks in any wires.
Every bulb is new. Every light socket is new. Headlight switch and ignition switch new.
The only thing not replaced at this time is turn signal switch and dome light (it works).
To be clear, I didnt buy all this just throwing parts at it. I did it because the truck needed to be rewired and most of the sockets were in poor condition after 45+ years on the road (shes been under the knife the last 4-5 years ).
She has had some serious TLC over the years. New paint. Suspension. Brakes. AC was ever reworked. Etc....
Really only thing original to her was frame and 80-85% of sheetmetal is original (bed was replaced @ 35 years ago and Ive done new cab corners and rocker panels)
But wiring had weathered and had been neglected, cut, spilced, etc....
So it was time for the wiring to be updated.

[pjmoreland]

See this thread. Same issue

https://67-72chevytrucks.com/vboard/...d.php?t=822068

[pjmoreland]

Very cool. It's gotta be satisfying getting toward the end of the project!

[Peepaw]

Originally Posted by pjmoreland

Very cool. It's gotta be satisfying getting toward the end of the project!

Indeed sir. Im getting there. This truck was put together May of 72, same month and year as me.
Then, on back of instrument cluster, a 4/27/72 stamped on it.
My son was born in the 4th month, my daughter was born on the 27th and I of course born in 72. Got some nostalgic going. 😳🤣