Brake lights and cruise work intermediately until 12/01/22, then stopped working all together?

Hello, the white wire at the Brake Pedal switch should be lit brightly with the pedal depressed, power comes directly from the Stop LP Fuse 25amp in the engine compartment fuse block, so you have a voltage drop from there. Do you have full power on the orange wire coming into the Brake switch? That is hot at all times from the same fuse. I'll post the diagrams and check the oem to be sure on the circuit. I would use a multimeter and see how much voltage is on the orange wire. Can I get your VIN too to verify the correct 1500 series vehicle,
Okay, the oem diagrams are the same, there is a connector (C202) inline from the fuse panel on the orange wire, I'll try to locate that as well. There might be a voltage drop across that connector.

https://www.2carpros.com/articles/how-to-use-a-voltmeter

VIN# 1GCEK19Z25Z356802
Model K15753

This is my style of connector, when I open the little flap to check wires themselves, I get the same result as I did through the connector. White wire Is dull, a "low glow". The other 5 worked as they should, the orange was constant, bright.
I will get you the voltage load of the orange wire shortly.
Thank you for your help Sir!

Thats the C202 connector? or is that the Brake switch connector, because that doesn't look like the correct one. I'll try your VIN and see if there's any change.
Okay, that's your brake pedal switch connector, but I see this difference here, there are 2 different labelled circuits, one is with this (JF4) and one is without (w/o JF4). So, I'm trying to figure out what that difference is but the diagrams I posted earlier are correct unless there's some difference with that label, I wouldn't worry about the other wires right now, both of these diagrams are from your vin. Are you sure you don't have a pin fitment issue at the brake pedal switch itself? Did you put an aftermarket switch in? According to the oem diagrams, 12v should be running directly through the switch when depressed on the orange wire to the White wire and that feeds the VEH Stop Fuse 15amp.
The 3rd and 4th diagrams are the entire Brake Lamp circuit, you can see how many connectors and locations this power supply runs to. If that Orange wire stays bright when the pedal is pressed and the white wire is still dull, then there is either resistance in the switch itself, or a poor pin connection. If it was something else pulling some of the voltage down on the white wire after the brake switch it would also pull down the orange wire as well.

What I would do, is put on meter lead on the orange wire and put the other lead on the white wire, set the meter to 20volt DC scale and press the brake pedal, see what the voltage drop is across the brake switch. I don't think there is any resistance inside the brake switch that's build in. It appears to me that there is some kind of voltage happening right at the switch,

2Carpros, whats going on?? I've responded to AL514, on 12/31 & commented again this mornining, Sat 1/1/23. Neither posted on here. Why?? What's the point in having a service like this if it's not solid 100% of the time 24/7??

Sorry about the trouble with your posts, this is the first one I've gotten since Dec. 29th. Sometimes when certain keyboard symbols are included in a post, it will not post it on the site, I believe this is to avoid getting spam posts which we have had a lot of in the past. So, try to only include letters and numbers in your posts.

Hello.. AL515 you still there?

Yes, I am here.

Still no brake lights. 3 Standard. 1 Duralast, 2 WVE brand switches and all giving exact same results, with 1caveat. While installing the 1st WVE I had to wiggle and apply a little more pressure to get it to slide last 16th of an inch, when I did my partner "yelled hey they're on". Confused, we tried to recreate it. After a bit we seen that if we pushed slightly on the side of the switch (around the center of it) and pressed the brake pedal the lights operated normally. As soon as you stopped pushing on the side of the switch and pushed brake pedal, nothing. We're able to repeat with all the other brand switches as well.
This led us to, "Were we installing it in the correct position? Was there more than 1 position it would even fit on? Or was there just 1? Much time has passed, and none of us remember for sure what the exact position of the one we took off was. I never thought to take a pic of it. I have been able to get all of them (New switches) in at least 2 or 3 different positions and nothing changes except, when you push slightly (or pull slightly) on the switch itself while pushing brake pedal. As soon as you stop pushing/pulling slightly on it, you can push brake all day long and nothing. Any Idea what this may mean?

Okay, when you say push on the center of the brake switch, are you saying that potentially putting pressure on the middle of the switch is causing it to make contact inside which it's not doing on its own? I'm going to look up the switch again to refresh what it looks like, but I remember you saying you were getting full power on the orange feed wire just not getting power out on the white wire. So, my thought would be pin contact. Possibly not the switch but the harness plug may have an issue. As for adjustment, you're going to want the brake lights to come on the first 8th to quarter of an inch of pedal travel, so they come on fast enough to alert the vehicle behind you. I think an 8th of an inch of travel is the spec but I'll look that up too. But I think you need to inspect the harness plug more. One other thing, when it comes to electronics, we always recommend buying an OEM part. A manufacturer part, because Duralast and other aftermarket parts are not to exact specs.

Something that comes to mind is that because the switch has not been making full contact for some time, but partial contact, this is actually resistance in the circuit, and resistance produces heat. So, check the harness connector for any discoloring or pins that got hot and possibly moved in the connector. If you can put pressure on the switch and make it work, then the issue is right there. Now if when you push on the switch and this is causing the pulling effect on the wiring harness, possibly pulling on another connector, then inspecting the rest of the wiring harness in that area is necessary.

There are 2 different part numbers for this brake pedal switch also, one is for an adjustable brake pedal, and one is not. And at AutoZone or some other aftermarket parts store they might not know the difference. So, they might be giving you the wrong part. But in the first diagram are both OEM part numbers as well as the best diagram I can find of the brake pedal switch assembly.

Okay, after trying the last Non-Adjusting Brake switch, WVE from parts plus (5th) the harness and plug were replaced even though there wasn't anything visible, outside of normal use. New harness is about 8' long, it was soldered, covered in electric grease and heat shrink, then black tape over. May have been a little much, I wanted to rule that out. We got the exact same result. It was at this point a buddy figured, what the heck, why not try a switch for adjustable peddles? So, he bought WVE switch (Parts Plus) for Adjustable brakes. His reasoning was that we've both used aftermarket part for years, they are what they are. We got same result as the 6th one...
When money and parts are there we use OEM. We knew the aftermarket is prone to fail, but 6 parts from 3 different Manufacturers all failing in similar or exact same ways. Something didn't add up. Trust me Sir, we're long past just spending the extra to get an OEM and hopefully be done with it, But no-one around me has any GM, AC-Delco, Delphi, made parts in. We've literally called 5 dealerships, random amounts of Napa, Advance, Parts Plus, Auto Zone, Oreily's, etc...They originally say a date between 0/16/23 to 01/16/23. Literally within a day, they'll call back with an "update", saying "their warehouse is out of stock" and they regretfully do not have any time frame that they will... Long story short ... Guess I'm stuck with the aftermarket. Which brought our thinking back to the switch and placement. Thoughts?

So, on your voltage measurements you're still getting low voltage on the white wire which would be the one coming out of the switch when depressed? Also, when you press the brake pedal, the section that actually pushes the switch in, is that rod misadjusted or was it moved at all while replacing the switch? I'm just asking because the diagrams I have of the pedal and switch are terrible and there isn't a good visual reference. I've done these brake switches before and remember it being a pain. Same situation though, intermittent brake lights. Can you get me a picture of the section that pushes in on the switch? And you were saying that if you push on the side of the switch, you can make the lights work? I think having a multimeter on the white wire and ground, watching the voltage, then checking to see if that rod is either not pushing the switch in far enough, or some other variable here we're missing. I know there is a push rod with a retaining clip, but I don't remember if it was adjustable or not. Because if you have 12-volts sitting on the orange wire, I would be concentrating on exactly what voltage is coming out on the white wire, and obviously its low, so does the voltage on the orange wire drop when the pedal is depressed, If it does drop, which would make voltage on the white wire and orange feed wire low, then there could be a voltage drop further down the circuit. You did something to make the brake lights work correctly at one point, so that needs to be investigated more. Check the orange wire and White wire while having the pedal depressed, do they both read the same voltage at that point? Find and check this connector too, C202. Just in case. The brake signal runs through it twice. Let's forget throwing anymore parts at it, and find this voltage drop.

And I know it's a pain getting a voltage reading on these, I remember having to, but we need to know if the voltage is dropping at the switch or somewhere else. Back probe the connector with some T pins and attach some clips to it so you don't have to hold the meter leads on there all the time.
Okay, I finally found a picture of the push rod for the brake pedal, this goes into the brake booster and to the master cylinder, but it's worth inspecting at this point. Take a picture of the switch for me if you can too.

One other thing, there are 2 bulbs for each side in the rear and these share the turn signals, are all the turn signals in the rear working? All other lights in the rear are working as well, license plate lights, marker lamps, etc. They all share a Ground Junction block.

I came across this fix on the All Data Community section, same exact issue you're having, and it turned out to be the aftermarket switches. OEM was the only thing that fixed this one. I'm looking around for an OEM one for you as well. Will update with further information.
Rockauto.com has Genuine GM parts, I don't know if you have adjustable pedals or not but they have the adjustable pedal brake switch in stock. If your voltage readings show the voltage drop is still in the switch, you can try them. You can measure the exact voltage drop by putting your meter leads on the orange wire and the white wire, and whatever voltage is lost in the switch is what you will read on your meter, that's a voltage drop test. Both leads on the positive side of the circuit.

https://www.rockauto.com/en/moreinfo.php?pk=371167&cc=1431121&pt=10474&jsn=543&jsn=543

Sorry for the delay, testing was not easy. It took 3 people but managed to get it done. The diagram below should give you an idea of what I have. All other lights in the rear are working as well, license plate lights, marker lamps, etc. Ground Junction block, wiring harnesses & Light fixtures & bulbs all New, including 3rd light above cab.
FYI, as far as throwing parts at it, I should let you know, I decided in Dec 2021, I wanted to do a complete "refresh" of all the lighting in & out of the truck, possibly the entire front clip.I've been stockpiling OEM parts hereuy & there since. A lot of little things were begining to go missing or getting worn, But nothing brake,turn,marker, fog or head light related have ever failed. Haven't ever had replace a bulb except a turn bulb once in the 4+years I've owned it. A lot of the things I've replace in the last mounth I've had on hand or were things already ordered, prior to this happing. Our money issue is recent, as I was holding off on getting more things for the truck when this accured. It's like someone "flipped a switched" & shut the brake lights off....Now I'm tryinto find That switch & turn it back on in the Dark...lol
We managed to get a meter in to test Wht wire while connected to switch & pressing brk. This was 4.7v to 5.3v consitantly.
we then pressed the side of the brake switch as shown in pic below. Brake light came on, meter read (lowest)11.7v to 13.3v(highest). difficut to do with 5 or 6 arms in a small space, but we managed to repeat about 3 times. So, like I said only seems to get power to switch when pressing on the side of it, If you can read my "chicken scratches" in pic.NOTE: now, Let me back up a little, before we replaced the switch harness, we put a meter to it. Probing the connector pin slot & the wht wire end dirrectly.Then we cut old harness connector out (Aprox 10") Before installing new 1, we tested wht wire, where we had just cut it. Almost exact volt readings as above. (within 0.1 or 0.2) The new harnes was just shy of 9" long(8 7/8" I think) We soldered it in check & double check it. Again same voltage readings (not pushing brake) 4.7v to 5.3v consitantly. Pushing brake (BUT NOT touching the switch) 4.7v to 5.3v consitantly, And then pushing brk & Pushing in Slightly on the Switch (as seen in Pic).Brake light came on, meter read (lowest)11.7v to 13.3v(highest).The only voltage loss we're seeing is when you remove slight pressue from the side of the switch it self.
Anothering intresting thing, is the 1 ADJUSTABLE switch that we've tried, worked 180degrees opposite, meaning push w/ index finger away from you, while pushing brk & nothing... Move your finger to directly opposite side of switch & PULL slightly twards you then press brk , Bam, works till you release pressure. Look @ the switches side by side (naked eye) they look the same. Look closer & you'll notice the are opposite, as a "Right & Left" side door handle would.
We believe that whatever is going on is mechanical & in the interaction between the push rod & the switch itself. Everything I can find says this truck was (factory)equiped with Non- adjusting Brakes, but nothing else really specific, LIKE ...."if you were looking at "push rod or booster", is there some sort of "identifier" that you would(could) tell the difference between the Non-Adjusting & the Adjusting?? Reason I ask is thus far, that's the 1st question we're asked when we've bought parts & we told them Non- Adjusting based off said data, never thinking anything of it..As of the end of today (430 CMT) we've contacted a least 7 different Chevy dealers service depts, and all of them conflicted w/ each other.Majorly. 1 told me, on Speaker for all to hear, that according to my VIN, it doesn't have Adjustable peddles & that the booster for Non- adjusting & adjusting peddles were physically different. That the Adjusting peddle booster could NOT be install on my truck w/o obvious (visually) modification. He then told me to go try to turn my push rod & I would see it doen't screw in or out it's stationary. He then said, the end of my push rod was round w/ a vinyal bushing in center of hole. So we hung up & went to check what he said. No obvious signs that booster was moddified or NOT original, infact still had the GM, QC name/date, plant & line (sticker) barely hanging on the bottom. We turned push rod 3 or 4 turns both clockwise & counter clockwise w relative ease & the end of rod that connects to brk peddle isn't round (see pic) nor does it have a bushing. So my calls the dealership back asks for that tech, then proceeds to tell him he needs to order a Brk switch, when asked for Vehicle Yr/make /model my buddy acts like he doesn't have it, but he has the VIN, tech takes the VIN, & within a min or 2 says "Adj or Non-Adj peddle, my buddy responds "ADJUSTABLE I think" within 30 sec, tech says "YEP It is, but I don't have any & wharehouse is out too, looks like I'll be able to get you 1 around the end of the Month. thats how our info "gathering has been going & frankly, Dealerships have given most confusing info of all involved.

Could be as simple as the push rod missing the bushing where it connects to Brake pedal?
thoughts?

Well, the voltage reading on the white wire while the pedal is not depressed is strange, although that circuit does go to a bunch of other components. As for an adjustable pedal or not, you would have a button that would bring the pedal closer or further away. The lack of that suggests this is just a basic setup. The round bushing I'm not sure on, are you able to press the brake switch button in if not connected to the pedal and get the brake lights to work? If so, then the pedals travel is not far enough to push the switch in completely. And the switches you have been trying need that bushing to work. I don't think there is any adjustment of the push rod through the booster on this, that would affect the braking power.
The fix I read about from other techs was that the aftermarket switch they had tried could be pushed in when not connected to the pedal and it would work but wouldn't work on the pedal, meaning the travel wasn't far enough. And the OEM fixed that issue. Every time Ivee looked up info on your truck, I've used the VIN. Which stated that it was a flex fuel set up, not that it's a difference here, but try using the switch plugged in and not on the pedal, it sounds like you might have a couple switches by now, if so don't bother taking the switch that's installed off the pedal, just plug in one of the others and see if it's a pedal travel issue. If the push rod is bent, this is what would happen then to. So, it might be something with the pedal or the lack of that bushing, why its missing I'm not sure on that either. I'm going to look and see if I can find any diagrams of the push rod that looks like yours, but I have seen that bushing with that bearing setup before.
I really don't know why the dealerships don't have a straight answer for you, I'll look for that bushing in service info.