Sorry, I wasn't understanding that both bulbs are supposed to blink and get brighter...still stumped on the cause though.

I've looked closely at the filaments over and over, replaced the bulbs and sockets, and it still acts the same. I wish I understood wiring diagrams better

 

This is what we're saying. They are supposed to both work. That diagram I posted is pretty simple.

I wish I could make you understand to start unwrapping the harness while the turn sig is flashing and wiggle wires. Thats how you will find it. either a wire is broken or it's got a bad connection in the next crimp or splice.

I wouldnt be surised if the culprit is at the end of the harness. That USUALLY means the problem is at the next connection down toward the power source

Put it another way. How many wires go to the socket that does not work?

How many wires go to the one that does work. I'm talking wires, not connections.

 

Looked at it some more. According to the diagram I've inspected and wiggled every connection that there should be for the right side tail lights. Every connection looks like brand new, I have not seen the slightest hint of corrosion or looseness anywhere, even the connections to the under hood fuse block. I'm sorry for my part in our poor communication. It's not that I'm not getting what you're saying (both of you), and I really appreciate the help. I think though, that this tail light is cursed.

 

The issue has to be between the splice that splits to the two bulbs & the bulb itself. Only one power wire comes back there so the issue has to be localized to between the harness pass-thru & the connector.

 

Please just answer this question!

How many wires go to the socket that does not work?

How many wires go to the one that does work. count the individual wires

 

Three wires going to the one that doesn't work, three wires going to the one that works. I didn't think I was actually supposed to answer that question, thought it was intended to be rhetorical and condescending. Plus, considering that your diagram shows how many wires there are um...

 

My diag doesnt show WHERE the two wires for turn sig are joined that is why I asked. I said to unwrap the harness from the socket that doesnt work backwards toward the source. Those wires do NOT go all the way to the front, individually.

The diag is a semi pictorial, that means it's part schematic which relates to connections and locationally accurate only to general area of join not specific location

And I'm not typing for the fun of it. You wanted help... I tried because I come from a little different angle than Kyle does; so how about you try to understand how we are thinking instead of thinking we're having fun at your expense.

I am saying clear as I can say it that if the connection at the socket isnt bad, then the connection where the wires from those two sockets join or splice is bad OR the harness has been stressed and wire broke under the insulation. You want to fix it? unwrap the harness until you find S418.

 

And I did what you said. I said that I checked every single connection I could find. I didn't remember ever saying that I disagreed with any of your ideas, and here I have been trying them and thanking you for the help. There was a short period where I admittedly wasn't sure if one or two bulbs were supposed to blink at once, but that is the only thing I can think of where I wasn't clearly stating that I'm right on track with trying you guys' thought I should do, letting you know how it went, and being overly thankful. Having fun at my expense? Well, it's clear that you aren't having fun, it seems that on the contrary you've actually gotten yourself all upset over my turn signal thread. And at my expense? Again, no, I don't know where you're getting that idea, but there's no need for all this patronizing heated stuff over a stubborn turn signal. I mean, all I've been doing this whole time is trying my best to understand where you two are coming from, trying to make sure I test things the way you suggest, reporting back, being thankful but still at a loss for what could be causing the signal problem. So I don't know much about electronics or diagrams, hence I'm seeking help. What is so frustrating about that to you? You're speaking to me as if you think you're having to tell me the same things over and over and I'm still not listening or not doing it- but what I've been trying to convey to you all along is that I've been doing to the best of my ability every thing you've suggested and there are no bad connections anywhere that I can find. See?

 

Lets get back to basics here. You need two things to energize a circuit. Power & Ground. If you don't have these two things, nothing will happen. So, how do we test for this? A test light or multimeter.

Do you have a multimeter? test light? Do you have some spare wire (enough to get to the battery)?

First you need to identify which conductors inside the connector are used for the filament that needs to light for the turn/brake.

Terminal G is the ground and will be a black wire coming out of the connector. This one is easy to check with a multimeter, but if the marker light filament in that bulb still illuminates when you turn your headlights on, the ground to the connector is not the problem.

Terminal A in the connector is the +12V into the turn/brake filament and is a yellow wire. This should have +12V whenever the brake is applied and/or when the turn signal/hazards are on.

If you have identified the correct wire, start by placing something on the brake pedal to activate the brake lights in the back (don't leave it on there too long with out a charger on the battery or you'll drain it). Then pierce the jacket on the wire with your multimeter or test light probe at the affected connector with the other probe of the multimeter (clamp on a test light) to ground. For a multimeter, this should show battery voltage; the test light should illuminate.

If it does, that means there is power going into the connector and the problem lies within the connector. This is regardless of what your visual inspection has determined. The next step would be to either replace the connector or to dismantle it to find the fault.

If it doesn't, then the problem lies between the location you tested and the splice joint. It could be a broken wire inside the insulation that you visually cannot see. Work back to the splice in that wire and you should find power somewhere along the way.

 

Well, I just now got it working mostly right. Thank you guys very much for the help. I still don't exactly know what the problem was. I had plenty of solder joints to touch a test light to because I recently replaced all the sockets to see if that would fix it. After a few minutes of confusion as to how it is possible that even though the bulbs were lighting, there was no power going to them, it dawned on me that the bulb in my test light was dead! So I got a little piece of wire and clamped it to the chassis, and touched it to the yellow wire of the socket that wasn't lighting, it sparked. The bulb looked fine, and it had to have been replaced five times throughout my diagnosing over the last couple years of having this stupid problem. When taking the bulb out and putting it back in, it would almost try to light (this is with the brake pedal held down), but then it wouldn't. Put another new bulb in it and it worked. I still don't think this is possibly the whole problem, unless I managed to put five defective bulbs in it before that all looked fine. Now it blinks almost normal speed. Still ever so slightly faster than the left signal, but I guess I can live with that...for now, especially since I'll never figure out how to make it perfect. Both bulbs in each tail light assembly now blink and get brighter when braking.

Thanks again!