Tail light mod (both lights used as brake and signals)?

yea...it acts like a heat sink

 

More resistance = less current (if voltage is the same).


The problem is that there is actually 3 types of electrical load (resistance, capacitance, and inductive loads) and people are using the term "load" without specifying which type of load they are talking about. To add to the confusion, load is also referred to as power consumption (ex: in summer, the AC's put a heavy load on the power grid). So we just have to be careful and clarify the meaning of "load" sometimes (which I'm guilty of not doing too).

Another problem is that the circuit is relatively simple until we add in the Turn as Tail module. Once we added that, we not only combined 2 circuits (the circuit for the brakes and the circuit for the turn signals), but we have now introduced a new sub-circuit in the middle of it all (the Turn as Tail module itself).

Despite all of this, it's still a relatively simple system once you brake down each of the circuits...but it's not something that will be easy to explain on this forum either.

I'm just guessing as to how the ECU is setup to detect a blown bulb, but it's probably just measuring the current draw to help it determine the resistance. Remember, the voltage is going to be relatively constant. So to find the resistance, it just needs to measure the current flow. It knows that the resistance of a bulb is within a certain range, so it knows what the measured current should be when the bulb is in place.

Now when put in the LED's, they are much more efficient and do not require much current to produce the same amount of light. The problem is, the ECU is thinking that less current, means more resistance. When a bulb blows, resistance technically goes to infinity (and current goes to zero)...but the ECU is not programmed to hyperflash at an extreme point like inifity or 0 because it's not a plain vanilla circuit. Instead, Toyota programmed a value that would be fine for halogen bulbs, but not for efficient LEDs.

So we have to add the resistor's in parallel to the turn signal LEDs so that the ECU see's the expected current & resistance for that circuit. But as I mentioned above, we've made this circuit a little more complex, so we are still trying to figure out what resistor value will reliably work for all of us. I believe 5 ohms works for some people, where others need 8, is because the resistors values can change slightly in different environments. The hotter a resistor, the more resistance it creates. So 5 ohms for me here in Hawaii might actually be more than it is for someone with that same resistor in a snow-covered driveway in NY.

Now, I bet that we have not had any issues with the LED brake bulbs is because Toyota had to program a wider value (range tolerance) so as to cover the many different possible states (parking lights on or off, is the 3rd brake light included with the circuit, etc) that the turn signal does not have to worry about. I suspect that there are more bulbs in this circuit that introduce more variables that they need to account for.

Sorry for the long post...hope it wasn't too confusing. lol

 

But a resistor is adding "fake" current correct? It sends some to the bulb and then some to ground (through the resistor). It's still confusing how my situation ended up.

 

There is no such thing as fake current.

In this case, adding a resistor diminishes the current (through wasted heat).

 

Hence the quotation marks around "fake" But wouldn't the current increase? The same amount of current has to get to the LED to power it, but then some also goes to ground via resistor. I thought this is what makes the truck think that there is enough. But as you said we don't know what it's measuring.

 

I'm too simple minded to understand all the nuances of electricity, but I'm hoping my complex issue will be resolved with a 8 Ohm resistor???

 

Most likely it will.

 

lol, I think you're going down the correct line of thinking.

Think about it this way. Given the same current and voltage (aka the same "power" measured in Watts), an LED bulb's resistance will be less than that of the halogen bulb while still producing a similar output in lumens. You can actually feel that difference with how hot the halogen bulbs get compared to an LED bulbs. So in order for the ECU to see the resistance it used to see with the halogen bulbs, we are adding the resistor which does (slightly) effect the current flow...but within tolerances.

Just remember that the resistor is being added in parallel (not in series), so it does not proportionally (linearly) change based on the amount of resistance we add. I think that's the part that may be confusing...

I have a feeling that it'll work out for you. Of course, this assumes that there is nothing wrong with the Turn as Tail module itself. I had that problem initially, but the DD guys quickly fixed that for me (great customer support)!

 

@OdiN1701 - everything still working flawlessly on your truck now that you have 9 ohm total resistors in? I am just kind of waiting to make sure all the bugs were worked out by the ones who have already attempted it. I hope to do it this weekend.

 

Yup I've had no issues since then.

 

Hell YEAH!! I'd be all over this if you do it just like this: v v v v v

This is EXACTLY what I have been wanting. Unfortunately, I can't afford your beautiful custom versions. Thanks, Stew.

BTW... Once you post these kits, if you want me, I'll be camping that "Purchase Now" PayPal button.

 

I'll revisit this mod offering after the first of the year and all my other little mods are done

 

I have a feeling that it'll work out for you. Of course, this assumes that there is nothing wrong with the Turn as Tail module itself. I had that problem initially, but the DD guys quickly fixed that for me (great customer support)![/QUOTE]
@ToyoDrew. I've had a tough time with the DD guys. I'm hoping things will change quickly. I'm getting FAR more support here than DD. As to the TT module working, the fact that it works now when I do not have the resistor in place mean anything?

I also wanted to ask you and @Double Phister. Why do I get no light output at all on my turn signal ( IN FACT, NO TURN SIGNAL ON MY DASH OR FRONT SIGNALS)when I do have the resistor hooked up?

 

@ToyoDrew. I've had a tough time with the DD guys. I'm hoping things will change quickly. I'm getting FAR more support here than DD. As to the TT module working, the fact that it works now when I do not have the resistor in place mean anything?

I also wanted to ask you and @Double Phister. Why do I get no light output at all on my turn signal ( IN FACT, NO TURN SIGNAL ON MY DASH OR FRONT SIGNALS)when I do have the resistor hooked up?[/QUOTE]

I've posted my findings before. But our flasher relay is hyper sensitive. Either too LITTLE or TOO much resistance will both cause issues. Either hyperflash like crazy, or the opposite(what you are encountering) signals flash once and then go dead completely(have to turn truck off and back on to reset it). The trick is finding the happy medium.

 

I've posted my findings before. But our flasher relay is hyper sensitive from my findings. Either too LITTLE or TOO much resistance will both cause issues. Either hyperflash like crazy, or the opposite(what you are encountering) signals flash once and then go dead completely(have to turn truck off and back on to reset it). The trick is finding the happy medium.[/QUOTE]
Always appreciate your input @mesojdm ! I'm still waiting for you to release the 3rd brake light mod!

 

My truck is new to me. I'm still in the pre-mod research phase. I'm just posting with general knowledge.

 

@toyomaniac71 What do you currently have installed now? 4 rear LEDs (2 brake lights and 2 turn signals) and the TT module?
Do you have any LEDs on the front turn signals?

Also, what LEDs did you buy? I ask because some LEDs have more resistance than others and some people do not need to add resistors...but they aren't using the TT module either

When I was testing things out, I noticed this as well. Too little resistance caused the hyperflashing and too much resistance caused it to signal once and then go dead.

So when I was testing, I wanted to see if it was worth keeping the stock bulbs as a backup (in case an LED died on me). I had the Turn as Tail module installed with the 5 ohm resistor and LEDs and everything was working fine. Then I swapped out one of the LEDs for a the OEM halogen bulb and it flashed once and then went dead (and yes, nothing on my dash or front signal either). Not sure why the ECU reacted so weird, but it's obviously due to too much resistance. I was just happy that it still worked once I restarted the truck. lol

I felt like I was dealing with my youngest child...he can be an overly picky eater sometimes.

Anyways, those OEM bulbs are now in the trash.

 

Probably worth it to pick up a spare set of LED's.

 

I was just thinking and how are you guys with issues connecting everything? Could an issue lie in the way it's connected? I soldered mine because I wanted a solid connection. I could be completely talking out my ass but it was just a thought I wanted to throw that out there you never know. Had mine in for just over a week with 8OHM resistors in each side with no issues so far so good. Oh and I did relocate the resistors to the black metal piece behind the taillight like in the previous post.

 

Doubt it. I did have and issue with one of the butt connectors on the DD module, so I removed those and replaced all with spade connectors. For the three wire point I soldered. While not an electrician, I'm pretty good with wiring.