Hyper Flashing Front Turn signals
Thread Starter
Intermediate
Joined: Feb 2018
Posts: 45
Likes: 2
From: georgia
Hyper Flashing Front Turn signals
Installed new LED switchbacks and soldered in the resistor in between the two positives. Connections are good but still having hyper flashing. Tried turning the bulb around and that did not solve it. Thoughts? Thanks
Melting Slicks
Joined: Oct 2002
Posts: 2,515
Likes: 441
From: Arizona
Melting Slicks
Joined: Jan 2009
Posts: 3,275
Likes: 739
From: Miami FL
Another disadvantage of resistors is that multiple ones are required (if you install LEDs in the tail lights in addition to the front ones, you would need a minimum of 4 resistors), while only 1 hyperflash harness is needed.
The most efficient way to solve LED hyperflashing is by installing a plug-and-play Hyperflash Harness.
In a C5 the turn signal and hazard functions are provided by the hazard switch. A hyperflash harness replaces the portion of the hazard switch that handles the turn signals with a flasher that's LED friendly. Hazards will still hyperflash because that function remains untouched in the OEM hazard switch.
Check this one out. It's completely plug-and-play: no splicing or anything.
Note: If you decide to install a Hyperflash Harness, don't forget to remove the shunt resistors you currently have. With this harness they are not needed.
Last edited by GCG; Jan 1, 2020 at 05:42 PM.
Melting Slicks
Joined: Jan 2009
Posts: 3,275
Likes: 739
From: Miami FL
Last edited by GCG; Jan 1, 2020 at 06:01 PM.
Thread Starter
Intermediate
Joined: Feb 2018
Posts: 45
Likes: 2
From: georgia
So will this replace all the resistors i have patched in? I think I wired some in a while back when I converted my headlights into led. Would I have to remove those? I'm sure the instructions will show me, but curious where does this plug into? Thanks again!
Melting Slicks
Joined: Oct 2002
Posts: 2,515
Likes: 441
From: Arizona
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Racer
Joined: Dec 2017
Posts: 331
Likes: 74
From: Florida
The most efficient way to solve LED hyperflashing is by installing a plug-and-play Hyperflash Harness.
In a C5 the turn signal and hazard functions are provided by the hazard switch. A hyperflash harness replaces the portion of the hazard switch that handles the turn signals with a flasher that's LED friendly. Hazards will still hyperflash because that function remains untouched in the OEM hazard switch.
In a C5 the turn signal and hazard functions are provided by the hazard switch. A hyperflash harness replaces the portion of the hazard switch that handles the turn signals with a flasher that's LED friendly. Hazards will still hyperflash because that function remains untouched in the OEM hazard switch.
Melting Slicks
Joined: Jan 2009
Posts: 3,275
Likes: 739
From: Miami FL
The built-in shunt resistors in the Halo tail lights (the aluminum block on their back) plus the LEDs themselves, draw just enough current to be above the threshold for hyperflashing when hazards are engaged:
Last edited by GCG; Jan 2, 2020 at 12:12 PM.
Melting Slicks
Joined: Jan 2009
Posts: 3,275
Likes: 739
From: Miami FL
It's fast and simple. You just need to remove the driver's knee bolster to have better access. The connectors you need to separate from each other, in order to insert the hyperflash harness in-between, are right there by the steering column.
Connectors should be directly below the ignition key switch:
Melting Slicks
Joined: Jan 2009
Posts: 3,275
Likes: 739
From: Miami FL
To prevent hyperflashing, the shunt resistors should go from the "Turn Signal/DRL/Hazard" positive to ground, not between the "Turn Signal/DRL/Hazard" positive and the "Parking Light" positive. In other words, the resistor needs to be connected in parallel with the LED bulb's turn signal circuit, so the total current draw becomes similar to the OEM incasdescent bulb's.
You could fix the connection, but I strongly suggest you follow the better solution and get a hyperflash harness. As you can see, the shunt resistors not only draw current for the brief moments the turn signals are engaged. Since that is the same bulb connection that handles the DRLs, that means they are basically always drawing current (except when the parking lights are ON), so they get extremely hot...
Racer
Joined: Dec 2017
Posts: 331
Likes: 74
From: Florida
With front "Turn Signal/DRL/Hazard + Parking Light" (4157 equivalent) LED bulbs AND LED Halo tail lights, some people have reported no hyperflashing with hazards.
The built-in shunt resistors in the Halo tail lights (the aluminum block on their back) plus the LEDs themselves, draw just enough current to be above the threshold for hyperflashing when hazards are engaged:
The built-in shunt resistors in the Halo tail lights (the aluminum block on their back) plus the LEDs themselves, draw just enough current to be above the threshold for hyperflashing when hazards are engaged:
Drifting
Joined: Feb 2001
Posts: 1,768
Likes: 297
From: Plano TX
I have LED DRLs with a switchback harness. I have several weird issues.
-- When I first start my car, I get a flickering in the DRLs ... as well as my HVAC panel lights.
-- When I turn on my turn signal, the HVAC panel lights will flash on/off with the turn signal.
-- If I turn on my headlights and then turn on my turn signal, the HVAC panel lights don't flash, but both turn signals flash.
Thoughts?
-- When I first start my car, I get a flickering in the DRLs ... as well as my HVAC panel lights.
-- When I turn on my turn signal, the HVAC panel lights will flash on/off with the turn signal.
-- If I turn on my headlights and then turn on my turn signal, the HVAC panel lights don't flash, but both turn signals flash.
Thoughts?
Instructor
Joined: Feb 2000
Posts: 193
Likes: 4
From: Houston TX
I only want to replace only the DRL/Turn signal bulbs (4157NA) with LEDs since the DRL/Turn Signal bulbs are the only ones that put a hole in the plastic enclosure and cook the bulb holders. I replaced the bulb socket holders a year ago and noticed the new ones are already showing significant signs of being cooked. Will the hyperflash harness work correctly having only replaced the DRL/Turn Signal bulbs with LEDs in the front? The resistors normally supplied for LED drop ins dissipate something like 15 watts and need to be installed on metal to safely dissipate the heat. I haven't initially found any metal surface near the headlights and I hate to see my electrical system run two heaters in the Texas environment. I also wonder if the height of the 4157NA replacement LED isn't taller than the bulb causing installation problems. The bulb must be awfully close to the top of the plastic enclosure since it has twice burnt a hole in the housing directly above the 4157NA bulb. I initially fixed the plastic housing 10 years ago and it cooked a hole in the fix within 8 years. Also could someone explain what they mean by term switchback which I see a few times in this thread.
Racer
Joined: Dec 2017
Posts: 331
Likes: 74
From: Florida
I have LED DRLs with a switchback harness. I have several weird issues.
-- When I first start my car, I get a flickering in the DRLs ... as well as my HVAC panel lights.
-- When I turn on my turn signal, the HVAC panel lights will flash on/off with the turn signal.
-- If I turn on my headlights and then turn on my turn signal, the HVAC panel lights don't flash, but both turn signals flash.
Thoughts?
-- When I first start my car, I get a flickering in the DRLs ... as well as my HVAC panel lights.
-- When I turn on my turn signal, the HVAC panel lights will flash on/off with the turn signal.
-- If I turn on my headlights and then turn on my turn signal, the HVAC panel lights don't flash, but both turn signals flash.
Thoughts?
I recommend Sylvania LEDs, which are pricey, but I've yet to have any of the multitude of problems that I read here on the internet. Phillips is probably also a good choice.
I only want to replace only the DRL/Turn signal bulbs (4157NA) with LEDs since the DRL/Turn Signal bulbs are the only ones that put a hole in the plastic enclosure and cook the bulb holders. I replaced the bulb socket holders a year ago and noticed the new ones are already showing significant signs of being cooked. Will the hyperflash harness work correctly having only replaced the DRL/Turn Signal bulbs with LEDs in the front? The resistors normally supplied for LED drop ins dissipate something like 15 watts and need to be installed on metal to safely dissipate the heat. I haven't initially found any metal surface near the headlights and I hate to see my electrical system run two heaters in the Texas environment. I also wonder if the height of the 4157NA replacement LED isn't taller than the bulb causing installation problems. The bulb must be awfully close to the top of the plastic enclosure since it has twice burnt a hole in the housing directly above the 4157NA bulb. I initially fixed the plastic housing 10 years ago and it cooked a hole in the fix within 8 years. Also could someone explain what they mean by term switchback which I see a few times in this thread.
Drifting
Joined: Feb 2001
Posts: 1,768
Likes: 297
From: Plano TX
What brand are you using? I recommend to everyone only using quality LEDs. Don't use the cheapest ones you can find, where you can do your whole car for $50.
I recommend Sylvania LEDs, which are pricey, but I've yet to have any of the multitude of problems that I read here on the internet. Phillips is probably also a good choice.
Yes the hyperflash harness will work, and is used as a better solution than using resistors. As mentioned above, its also good to get some better brand LEDs like Sylvania.. They use alot of engineering to get their LEDs to match resistance, and impedance of filament halogens. Switchbacks refer to LEDs that mimic modern cars where the daytime running bulb is white, and then "switchbacks" to turn orange when the turn signal is activated.
I recommend Sylvania LEDs, which are pricey, but I've yet to have any of the multitude of problems that I read here on the internet. Phillips is probably also a good choice.
Yes the hyperflash harness will work, and is used as a better solution than using resistors. As mentioned above, its also good to get some better brand LEDs like Sylvania.. They use alot of engineering to get their LEDs to match resistance, and impedance of filament halogens. Switchbacks refer to LEDs that mimic modern cars where the daytime running bulb is white, and then "switchbacks" to turn orange when the turn signal is activated.