no rear lights?

Sorry to hear about your dad, I still miss mine, let's get this fixed so you guys can ride once again. The white wire coming from the fuse panel might go the brake light switch. here is a wiring diagram so you can see how the system works. Once the wiring is repaired let's check the fuses which the wiring diagrams will show you that run the system. I have included the fuse locating as well. Please go over the diagrams and fuses and upload images of any question you have so the light will start working again.

https://www.2carpros.com/articles/how-to-check-a-car-fuse

and

https://www.2carpros.com/articles/how-to-check-wiring

Check out the images (below). Let us know what happens and please upload pictures or videos of the problem.

First of all, thank you for responding back and willing to help it means a lot. just so we on same subject the white wire I'm referring to is coming from fuse box and the brake lamp relay is in spot where wire is coming from n not attached. I'm trying to see where it would splice in a wire for brake light switch because white wire is at most 4 inches long so can't go back in fire wall. Going out to truck here in few minutes and will take pictures of wiring and so that way you can see and know exactly what I'm talking about clearly and able see what I'm seeing.

That's the white wire I am asking about don't see where old one is or where it connects to.

Okay, using a test light turn the key on to see if the wire has power, if not put power to the wire and then see if the brake lights work. If there is a big spark when power it connected, stop. Please let me know.

Okay, so is there a certain wire I hook up to or just use a wire with power to it? Also use a constant power or a power with key in the on position? Come to learn guy that supposedly knew what he was doing when didn't had replaced fuse box and cut old wires to wire in new one and didn't connect all wires and ran different wires to third light to get power to other rear brake lights. Asking about wires so I'm hooking up right to figure out and as you say to. Again, really appreciate the help and time and advise you giving me especially your time responding.

No problem, I did see the wiring and was wondering what happened, yes use a wire with small alligator clips which we will use for testing. it will look like this. We will get this fixed up for you.

Okay, so got power to it and it's working way it's supposed to when brake is pressed. When turn lights on everything turns on and works except no parking lights in the rear but do have brake lights if I apply the brake. If you press the hazard light button on steering column, they flash in rear. So, I have all the lights in front working have flashers in rear, all brake lights working but no parking lights in rear. Thanks for advice on brake light issue and getting it repaired.

Okay, the brown wires supply voltage to the running lights, if you have running lights in the front run a wire from the front brown wire to the rear brown wire and that should fix it. Let me know.

Okay, will try that and let you know. Question got another issue all of a sudden come out to start up truck and it will crank but will not fire over at all. Now just did all new plugs and wires already checked to see if get fuel to engine from fuel rail pressure valve it is getting fuel none of spark plug wires are arched or exposed after turning it over for few seconds it makes like a backfire noise in the air filter cabin. First time ever did this never had issue with it starting up before had it running for over an hour yesterday and ran perfect no problems never shut off not any noises or smoke at all was running and sounding great and now nothing at all must cranks and cranks. It's like it's not getting spark now to fire it over. Had a similar experience with an 1985 chevy caprice years ago turned out to be the ignition module I believe it was it sat right under distributor cap was white and flat and then it was can remember wat it was called but it was round black hard rubber in middle and a metal square housing around it it also was connected to distributor cap and had wire connection plugs to it. But that was am 1985 Caprice this is 1997 GMC suburban.

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Cheers, Ken

Okay, got rear lights working like should just one issue still. Checked all fuses and tested lights. So, what is going on now is press brake pedal and rear brakes lights work use turn signal left n right and works in rear turn on parking lights and nothing still. But now if take rear light assembly off and disconnect light and use tester light it has power to all wires in the rear light assembly on both sides and all other parking lights are working just don't have no parking lights in either side in rear.

Can you test the brown wire when the running lights are on for power? (Rear harness). Also, did you try to run a wire from the front running lights (brown) to the rear?

Yes, there is power on both sides at light assembly in rear. Test lighted all wires in connections during each wire did what supposed to do the brake lights light up when pressing brake yellow wire driver side rear make lights blink up test light all lights work right just has no running/ parking lights. So quick rundown and hopefully helps you and knocks it down to figuring it more less what is causing this. Have all functioning and working lights in front of truck in rear have turn signals have hazards if press it. Has brake lights when press brake pedal but turn light switch on dash on to turn on lights no parking lights in rear.

Yep, because there is power on both sides the ground is bad. check out this guide which can show you what I am talking about:

https://www.2carpros.com/articles/no-tail-lights-exterior-running-lights-tail-lights-out

and

https://www.2carpros.com/articles/turn-signals-not-working-blinker

Please go over these guides and report back. If you can shoot a short video and upload it of the problem, I can better understand what's going on.

Here's a short video of my issue that I'm going through with taillights. Sorry about the shake video it's just me recording or trying to holding my tablet n not trying to drop it.

Nice work on the video, if you have power at the rear brown wires and the other lights work like the brake lights then it must be the light housings or bulbs, can you make sure the correct bulbs are installed?

Okay, and thank you on comment of video. So, after getting it all back together i noticed all the lights were functioning well, almost all. If you start the truck up and press brake pedal rear brake lights, come on even 3rd light on top. Both turn signals on left side work front n rear same as for right side, all hazard lights flash as supposed to. Here is the puzzling part: when I turn on my lights all the lights around truck come on as they should but now yes, my rear taillights are showing on but when looking closely notice all 3 brake lights are on as if pressing brake pedal and I'm not. but turn lights all off and all lights are off and brake lights off too and will turn on if press pedal. i also noticed that there is another wire a light blue thick wire that comes from under the brake light relay under hood that was not wired together with another light blue wire its connected to a white wire coming out of firewall in engine area which looks to be wiring harness that traces back to rear lights wiring. So, me being curious i disconnected lt blue wire from white harness wire and it causes me to lose brake lights when pressed and causes me to have no lights when i turn on lights switch on dash. but connect wire again and i can hear the brake light relay click and taillights are on again and has brake lights again disconnect light blue wire again and no lights. Can it be possible that the light blue wire and white wire that are coming out under the Brake Light Relay in engine compartment are spliced into wrong connection point. Because if i disconnect white wire it does exactly the same thing light blue wire does causes to lose all rear lights when lights are turned on and loses brake lights if pressed. So, it's all acting correct if drive during daytime I'm good but at night can't drive because looks as if I'm riding brake pedal even when not but do have all lights working even reverse light is working when put in reverse. Now that's with those wires connected if either wire is disconnected i have no brake lights or taillights. after looking over and under and all thru area wires are in cannot for life of me find anywhere else these wires are able connect to and diagrams you sent me there showing connecting to harness for brake light switch and to directional switch but wires not long enough to connect to them. I came to conclusion that either brothers buddy cut wires to short and thats why i am not able to locate where attach at and that my issue is between relay wires wired wrong under hood compartment between the light blue wire and the white wire.

It sounds like the wiring is messed up, I would trace each wire and test it with the wiring diagrams and guide above to see if they are connected, this will take a while, but it should get us to the problem. Also, I have seen the rear bulb housing melt and connect internally which causes issues as well.

Traced followed each wire and they all are running n connecting as diagrams are saying should. Tracked it down to 2 separate wires but both coming out from the brake light relay under hood. The terminals that the brake light relay connect into are the 2 wires I have traced my issue to its that white wire and a light blue wire from relay that isn't wired correctly. In the diagrams you sent me all of them show white wire from brake light switch to brake light relay are to connect and shows light blue wire connecting to the turn signal switch wires. The way they are connected is white and light blue connected with a thick pink wire from fuse box all together and then about a half foot down the harness the white wire is connected to brown wire and light blue connected to white wire in same harness going to rear lights to connect to light assembly. And both light panels on each side were replaced already.

Okay, that is good to hear. so, did you see where the wiring is messed up?

Well, yes, I located exactly where the mess up is located and I am able to get directly at wires just can't locate where they would attach to the wiring as says in diagrams. I'm going to add a few pics of the cluster he'll of wires and what I'm unsure of exactly. You will see white wire referring to you about and the light blue wire attached to pink wire. White and light blue come from brake light relay slots.

Isn't allowing me to upload pics right now says file type not allowed. But soon as I am back at home will take pictures and send them over.

I am hoping those pictures can help you out and explains it more to you than I have. As I said in other messages the white wire and light blue one spliced into pink wire are my 2 in question an unsure and unknown of where connect at.

Well, yes, I located exactly where the mess up is located and I am able to get directly at wires just can't locate where they would attach to the wiring as says in diagrams. I'm going to add a few pics of the cluster he'll of wires and what I'm unsure of exactly. You will see white wire referring to you about and the light blue wire attached to pink wire. White and light blue come from brake light relay slots.

When it said file type not allowed can you tell me if you are using an Apple phone? Yep, that wiring is messed up, all you can do is trace and fix each one.

It doesn't allow us to upload pictures already stored in device it has to be a live picture you upload. But I got it and it took me all night long to track them wires and my tracing down comes to under hood at relay box those 2 wires are cause of issue and can't locate where to connect them to and can't find on diagrams where each wire splices in with another wire. Starting to get frustrated with it all broke down this morning and started to cry and told my dad not sure if I get to take us riding again or get this fixed and am sorry couldn't get it done. But my wife told me not to give up and to see what u (Ken) says and what he can help with finding out. She knows how much it really means for me to get it driving right. It's just so time consuming when dealing with electrical on car because it could be anywhere in wires to find short or crossed wire but it's between them wires that is messed up. If the junkyard wasn't all the way across town, I go to it and search for truck like it exact year and see what these 2 wires attach at and connect into. It's beginning to seem like I'm going to have to do that just got to get motivated to do the almost 3 hours to walk there and 3 hours back but at least I could see in person where goes and connects into.

An answer to if i was using an Apple iPhone or product no it was Android phone but i tried upload picture from photos and guess not allowed to can only upload and send video and pictures that record or take picture of right then and got to take and upload with camera feature in app.

Okay, thanks for letting me know, I would follow the wiring test guide to check the connection to each wire in the wiring diagrams. You should be able to find the open connection.

Okay. So, to brief you really quick, I had a set back and was forced to put things on hold with the truck. The other day someone tried to steal my truck. damaged the driver's door handle and lock cylinder to where can't unlock door with key so had to get new locks with keys and door handles. and truck did not have battery in it took it in house to utility closet to charge it up. so wasn't like they were going to get it started n get away.
So, where I'm at and stuck at are these two wires coming from slots under the brake light relay under hood. i got a white wire and a light blue wire coming out of the slots under the same relay. White wire is normal size and it's not a thick or different than a standard wire used for speakers. The light blue wire is thicker and about the size of the power wires running to maxi fuse to supply power. Cannot and do not see any where possible the wires were able to attach to any unless connects to wires in fuse box because that's as far as wires can reach to.
Now will tell you this though i put light blue wire and white wire together on a power supply and low n behold press brake and got brake lights but when turn on headlight switch i have tail lights or so i thought but it's the brake lights and reason say its brake lights and not taillights is because the 3rd brake light was lit up if was tail lights 3rd brake light wouldn't be lit up unless brake was pressed which wasn't the case. I disconnect them 3 wires and back to nothing.

But i do have power at rear taillight assembly connections light assembly bulbs light up when supposed to but if turn on parking lights all lights come on, but taillights are on because the brake lights are on all 3 brake lights are on. but turn signals work like supposed to reverse lights work when put in reverse brake lights work when press brake but when turn on lights' taillights are only on because brake lights on. if pull one of wires from white one and light blue one and whichever other one is losing all functions in rear taillights.
It all narrows down to the relay under hood for the brake light relay the wires the relay plugs into is ones need to figure out exactly where splice into and it clean up all the light issues having. dude never should have replaced fuse box under hood or done it correctly not just cut wires and splice in what he could match up and need to get truck started and drivable. brake light relay plugs not wired in to correct way had no brake lights so he ran a power wire from 3rd brake light to driver side taillight assembly to put power to the rear assembly so brother could drive it to sisters until i got it just stuck on these 2 wires.

Yep, you might need a new wiring harness if you can't fix that one. I noticed it was a mess so you must rewire it correctly or get a new harness, you might be able to get one from a wrecking yard.

It's really beginning to look like it's what is going to be best decision and on top of it all it saves me whole lot of time and keeps me from getting headache over the dumb stuff people do to get money out of people. Going to scrap yard in morning hopefully be able find harness if not at least hope to find truck not touched in area I need to figure out wires connect at. Will reach out tomorrow and let you know how it's looking and going with wire harness search.

Sounds good, sorry about the wiring mess, it can be a headache but we will get it fixed.

Okay, so catch you up to speed with the situation of taillights. Come to discover little brothers' friend one told dad he could get truck lights fixed and this and that told dad the whole fuse box under hood needed replaced to only come find out the fuse panel box he got and put in looked identical until get the one person who really pays attention and I'm that person. So key thing to it all and question is on old fuse panel under hood there was no brake light relay.in fuse box, but now this fuse box has 4 wires in rear of fuse panel. Since noticing fuse box is different, I'm betting all on issue is trying to trace down wires in harness to discover the 4 wires from stop lamp relay are a light blue one, a white one, a black one, and a red one. I and absolutely at all nowhere in electrical wiring or in wire harness are there 2 same color wires cut and loose to connect to. I'm really thinking and am almost positive this fuse box isn't for truck n brake light relay doesn't connect in wires. Is there 2 totally same fuse box just one not with brake light relay slot n wires. Will send over pics of each one so you can visually see what I'm talking about.

Okay, once we get the fuse panels side by side, we can see what's going on.

Okay, working on pics to send in just have crappy weather out here today. And I have am limited to what I am able to do when rains or storms hit. But I will get side by side pics, but I do know the fuse panel now has connectors for Brake Light relay as for original fuse panel doesn't have stop light relay in slots new one is in.

There are a few pictures of the original fuse box under hood in truck that came in truck. As can see no wires were pried out or damaged to say any was. So, tell me no fuse or relay was ever in the slot. Next with fuses and relays

And here's pictures of original fuse box with fuses and relays where they can connect. Now before comments come in, I am aware of the 2 maxi-fuse 30A that isn't in slots in pics. Don't have any extra around anywhere. But everywhere else that can put fuse in is in it.

Going to get pictures of fuse panel box that's in truck now and has me wondering.

As you see more wires and relays on this fuse panel than on the original fuse box the came in truck originally. There's pictures of fuse panel in truck that for unknown reason dude decided tell brother was problem when it wasn't than but it's what's the problem now.