LED Turn Signal Bulbs (Front & Rear) Upgrade: Resistor Problem

[CruelJung]

I set out to upgrade all 4 of my turn signal bulbs to LED on my 2008 Yukon XL and things did not quite go according to the plan, which leads me to a few questions:

1. Are our front and rear turn signals on the same circuit, per side?
2. If yes on "1," should I be able to use a single 3 ohm (4.5 amp) resistor on each rear turn signal to supply the load for both front and rear?
3. If yes on "2," is there a specific place on the wire path (farther upstream than the wires directly behind the tail light housing) where I should be tapping in with the resistor (3 ohm, 4.5 amp)?


With the questions out of the way here's some back story:

I have already been running LED head lights, fog lights, side markers, and reverse lights for a couple years with no problems. Recently, I decided I may as well upgrade the rest and ran into the 'hyper-flashing' scenario. After digging around this site and some others, as well as feeling mildly experimental, I came to the conclusion that I might be able run one large/double resistor tapped into the rear turn signal (per each) that would supply the total load required for the front and rear turn signals.

I liked VLED's VLR-3 for the resistors, LASFIT's L-Series for the brake and rear turn signal, and SEALIGHT's model for the front turn signal/DRL bulbs.

After installing the resistor and the new bulbs on my driver side, however, my turn signals were hyper-flashing. Then, I changed the front turn signal bulb back to the original incandescent and the hyper-flashing stopped--with the LED brake light bulb and LED turn signal bulb still in the rear tail light. I also experienced hyper-flashing with other configurations (no turn signal bulb and incandescent turn signal bulb in rear), as long as the LED bulb was installed in the front turn signal.

After speaking with the VLED installation department and considering all the threads I have seen on this forum about this topic involve using 6 ohm (2-2.5 amp) resistors on all four turn signals, I am under the impression that my current set-up is supplying more than enough load for my rear turn signals to not hyper-flash but that load is not being supplied to the front. The VLED employee recommended that I remove the 3 ohm/4.5 amp resistors, as they could damage my BCM, and replace them with a VLR-6 on each individual turn signal being changed to LED. He also said my vehicle not having the front and rear turn signals, per side, on the same circuit was very unusual.

I still have the 3 ohm/4.5 amp VLR-3 resistors and LASFIT L-Series LEDs (rear brake and rear turn signal) installed on both sides with incandescent bulbs in the front (turn signal/DRL), with no hyper flashing.


Any insight/ideas on why my intended setup did not work or how/if I could make it work would be greatly appreciated. Also, on the technical side, will keeping these larger resistors in place (as they are now) harm my BCM?

Thank you!

 

[Doubeleive]

you need 6ohm (standard) on all 4 corners, you can get them cheap online, get the ones that have a heatsink and screw-mount to the body, otherwise they get hot and melt the wiring.
the yukons are "tricky" for the front because there is a 5 way splitter, you have to get just the right wire combo or it will not work and will create a multitude of errors, I did mine years ago and it has long been a set it and forget it thing, I will try and find my post showing the correct wires that need the resistor in the front.
I mounted mine here

and the connection should be something to this effect

 

[Joseph Garcia]

You are receiving great advice above on how to resolve your issue.

I kept the hyperflash, because it is more noticeable to other drivers on the road around you, and isn't that the purpose of a directional after all? I will note that hyperflash is illegal in some states, though.

 

[petethepug]

It’s your body control module / BCM that’s freaking out.

* You can buy a $4h program to reprogram the BCM to shake hands with the led.

* Add the resistors into the circuits.

• Purchase bulbs with integral micro fans that extend the life of the bulb by cooling them as well as taking the place of the needed resistor.

 

[CruelJung]

you need 6ohm (standard) on all 4 corners, you can get them cheap online, get the ones that have a heatsink and screw-mount to the body, otherwise they get hot and melt the wiring.
the yukons are "tricky" for the front because there is a 5 way splitter, you have to get just the right wire combo or it will not work and will create a multitude of errors, I did mine years ago and it has long been a set it and forget it thing, I will try and find my post showing the correct wires that need the resistor in the front.
I mounted mine here
View attachment 450361
and the connection should be something to this effect
View attachment 450362

Thanks! I really wanted to avoid putting resistors everywhere and took the absence of (or my inability to find) a conversation in these threads about using a 3 ohm/4.5 amp resistor per side as a green light to try, but it looks like I will be applying the same method as everyone else in the end. Electrical work is the next frontier for me, but I've yet to take the learning dive outside of solving a limited number of localized issues.

I do have a Haynes manual (which includes wiring diagrams) for help, but--due to the aforementioned electrical ignorance--I just relied on a YouTube video (wires to tap at 4:55) for selecting the right wires in the rear turn signal harness (black/ground and yellow/turn-blinker). It seems like I got the right ones for the rear blinker, since I have no hyper-flash with my LEDs installed back there (with incandescent in the front).

I appreciate the photos. When switching the front turn signal bulb, I was lazy and just removed the top headlight bolts--gently pulling the head light out enough for me to rotate the socket with two fingers for bulb access. Point being: I haven't thoroughly investigated yet, but that is about the same spot I considered for mounting a resistor (from my limited vantage point at the time).

I will be sticking with VLEDS and have ordered 4 of the VLR-6 (50w/6ohm) resistors, which are lower in profile (depth) but larger in foot print than the style you used. This may mean I have to do things a little differently to keep the resistors isolated from wires/etc., but I will figure something out. I should have the VLR-6s and some additional mounting plates (just in case) within the next two days.

The main reason why I like the VLEDS resistor is the duotap/resistor cable junction. I can theoretically replace the resistor without having to deal with my factory harness connection points. I do also think the design and construction are above average in quality, but I am largely giving the company's specs and claims the benefit of the doubt. Only time will tell.

I will upload some photos after I've ensured the install was successful.

You are receiving great advice above on how to resolve your issue.

I kept the hyperflash, because it is more noticeable to other drivers on the road around you, and isn't that the purpose of a directional after all? I will note that hyperflash is illegal in some states, though.

I think I read your original post about that when digging around this site. I am 100% with you on the attention-getting value of hyper-flash and I don't believe it is illegal in my state, but my M.O. is to be as stock as possible in outward appearance. My theory is that it avoids unnecessary police attention and makes it just a little bit harder for anyone to easily identify me on the basis of a unique quality.

My vehicle does have some unique qualities, but I just try keep them to a minimum if possible.

Nice Whipple build, by the way!

It’s your body control module / BCM that’s freaking out.

* You can buy a $4h program to reprogram the BCM to shake hands with the led.

* Add the resistors into the circuits.

• Purchase bulbs with integral micro fans that extend the life of the bulb by cooling them as well as taking the place of the needed resistor.

Thanks!

Well, it seems I will have to swap out my two 3ohm resistors for four 6ohm resistors.

I noticed most of the LED bulbs for my front DRL/turn signals with integrated resistors or fans seemed to not have forward facing diodes. This was a concern of mine for visibility, as a light of that style would rely entirely on projecting backward into the reflective material in the housing.

I tried the Sylvania LEDs (readily available at Autozone and require resistors), which operate that way due to a large heat sink in the front-most part of the bulb, and I found them to be quite dim (mainly during the day) in contrast to the original incandescent bulbs--which produce visible light from nearly every angle and reflect backward. This experience lead me to my current plan, but some other resistor-free options may be perfectly bright and visible.

Presuming I don't have issues tapping the right wires up front (or some other problem), I will upload some images of the final installation with the 6ohm VLEDS resistors on each turn signal.