Wiring turn signal question, purple wires

[pjmoreland]

Originally Posted by Peepaw

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. 😳🤣

Haha, nice. It's easy to get attached to one of these trucks when you spend so much time working on it.

[BigBird05]

Check to see if the tail light wires are in the right location in the socket. Sounds like a back feed cancelling out your left light. Or your right light is trying to get a ground thru the left light bulb filament.

[Peepaw]

Originally Posted by BigBird05

Check to see if the tail light wires are in the right location in the socket. Sounds like a back feed cancelling out your left light. Or your right light is trying to get a ground thru the left light bulb filament.

Im gonna pop off turn signal switch (have new ome ordered, just gonna go ahead and install the new one), and Ill check the other items you mentioned.
Very close indeed

[pjmoreland]

A quick test of the turn signal switch would be to see if you have continuity between the white wire (power from brake switch) and the yellow wire (left brake light) at the U connector when your right turn signal is turned on.

[Peepaw]

Originally Posted by pjmoreland

A quick test of the turn signal switch would be to see if you have continuity between the white wire (power from brake switch) and the yellow wire (left brake light) at the U connector when your right turn signal is turned on.

I have not checked that. Will give that a looksie. Thank you

[Peepaw]

We had baseball late last night, so didnt get a chance to get any work on the truck. Will check turn signal switch tonight.

[aggiegrad]

I am pretty sure that you will fix the brake light issue by changing out the turn switch. I was skeptical but the $40 ac Delco switch fixed the problem and seemed high quality. I started to try to clean the old one first but I am glad I just replaced it. the old one was really loose and wearing out through the years. The only issue with the new switch is that it has a newer looking round hazard knob in stead of the old red lever. They also have an adapter that fits the u shape plug as the switch is more universal now.

I will say that the shifter is much smoother as well now as I was able to grease everything while putting it back. I am glad I spent the time. There was a good youtube video that I found that walked me though the process of changing it out.

Let me know if you have any questions. If you are in Pearland you really are not that far from me.

Bryan

[Peepaw]

Originally Posted by aggiegrad

I am pretty sure that you will fix the brake light issue by changing out the turn switch. I was skeptical but the $40 ac Delco switch fixed the problem and seemed high quality. I started to try to clean the old one first but I am glad I just replaced it. the old one was really loose and wearing out through the years. The only issue with the new switch is that it has a newer looking round hazard knob in stead of the old red lever. They also have an adapter that fits the u shape plug as the switch is more universal now.

I will say that the shifter is much smoother as well now as I was able to grease everything while putting it back. I am glad I spent the time. There was a good youtube video that I found that walked me though the process of changing it out.

Let me know if you have any questions. If you are in Pearland you really are not that far from me.

Bryan

That is what I am thinking as well. I hope to have the turn signal switch diagnosed properly this evening.
I get off work at 6:00, home by 6:20, have baseball at 7:15 tonight.

So, have @ 15-20 minutes to check signal switch.
If not tonight, definitely tomorrow (and my new switch should be here today/tomorrow as well), but Id like to test old one (now that I have been given info on how to test it) so I can compare notes with new one.

But I have taken every single light/lamp, and gone directly to them and tested them, and they work (correctly wired up).

So we'll see soon enough.

[pjmoreland]

Another way to test the turn signal switch would be to plug your new one into the truck harness loose under the dash and see if it fixes the problem.

[pjmoreland]

If you were to unplug the turn signal switch U connector from the harness, then you could measure the resistance between the white and yellow wires of the switch when the switch is in the right turn position. You should get a nice low resistance reading.

For comparison, you could put the switch in the left turn position and measure between the white and green wires.

If your multimeter has a continuity setting where it beeps when the probes are connected together, use that setting.

[Peepaw]

Well guys, we got her!

It was turn signal switch. All this head scratching, and bouncing ideas' and going absolutely mind pulling hair out crazy, it was turn signal switch.

I have been doing this long enough (albeit, wiring is NOT my thing) to know to never assume anything and I assumed it was something I had done (in the process of wiring the truck up).

I was 90% done with the wiring, had it all looking great, routed properly, etc...to only pull EVERYTHING apart thinking it HAD to be an issue with what I had wired up.
What makes matters worse is that I had bought everything for replacement (bulbs, headlight switch, ign switch, new fuse box, all new wiring from front to back and the ONLY thing I had not bought was turn signal switch.
Why on earth did I not buy one while I was in the process of doing this?!?!?!!?
My only explanation is that it was to teach this old man something, or drive that point home even further, NEVER assume anything.

I appreciate everyone's input and advice. Id say 99% of what was told to me was put to use. I listened to everyone, and in doing so I DID find some small mistakes I had over looked (ground cable/wires...needed better ground for sure).

But again, thanks again for all the input.

I do have a build thread going, and I am going to get some work done on her this weekend and will have some more updates and pictures of teh process.

[pjmoreland]

Whew! I was getting a little nervous after you spent money on a new switch. I'm glad it worked out. I will check out your build thread.