How to get switchback LEDs to work

Have an electrical problem? Lighting, Alternators, gauges, DIC, HUD, etc? Post it here. Please post Audio problems in the Audio forum, and Engine control problems in the appropriate Mechanical forum for your year.
Post Reply
User avatar
J Wikoff
Administrator
Administrator
Posts: 17080
Joined: Mon May 19, 2008 7:01 pm
Year and Trim: 1992 SSE
2009 G8 GT
Location: Central Illinois
Contact:

How to get switchback LEDs to work

Post by J Wikoff »

I tried switchback LEDs, both random Amazon brand and Diode Dynamics, and they are always yellow. Never white like they should be when on as parking lights. I am talking about the turn signal bulbs in the headlights by the grill. They are 2057 bulbs.

I've done some multimetering and some stand-alone voltage regulating.

On as parking lights:
Pin A has 10v
Pin B has 12.5+ (running system voltage)

When turn signal is on:
Pin A cycles between 12.5+ and 2 volts
Pin B has 12.5+

With the voltage regulator and the LED in hand, the only way to get the white light is when only pin B has voltage. If both pins have voltage, it is yellow. Even when they both have just 10 volts. Seems like I need to get down below 7 volts before nothing lights up.

So to make the LED switchback like it should, I would have to block the voltage above 7 volts to pin A while the parking or headlights are on, but allow voltage to pin A when the turn signal is on.

How would I accomplish that?

Image

Image
Image
WHITE WHINE - 1992 SSE Supercharged 236.26 ci (.040 Over) 15.090 at 90.2 MPH on old engine w/ slipping trans & melted O2 sensor - Gen 3 M62 and matching TB, Gen 2 Pully, Zillamotorsports Ported LIM, YT 1.72 Roller Rockers, SII FPR & Injectors, Hypertech Thermomaster chip w/ 160 Thermo, TransGo Shift Kit, Infinity/Pioneer Speakers & a 10" Alpine Type R Sub, all the watts, 140 amp Alternator, Ricepipe CAI w/ heatshield, Pilot Angel Eye Foglights, Clear Corners, '02 17" Chrome Bent 5's, Magnaflow F-Body Muffler and Hi-flo Cat, Ceramic Coated Ported Exhaust Manifolds, Fan Override, Monroe Reflex struts, red calipers
2009 G8 GT - Sport Red Metallic, loaded, SOLO Axlebacks, Rotofab Intake, Tuned, autodim mirror, removed intake manifold cover, HSV GTS triple gauge pod, two tone red-hot shifter and HSV SuperSport steering wheel, GXP rear sway bar and diffuser, 3.45 diff and various Camaro suspension bits, LED Taillights
User avatar
95naSTA
Certified Bonneville Nut
Certified Bonneville Nut
Posts: 7087
Joined: Wed May 21, 2008 11:47 pm
Year and Trim: 95 SLE
Location: Philadelphia
Contact:

Re: How to get switchback LEDs to work

Post by 95naSTA »

What would happen if you used Ohm's Law and add resistors to get the resistance and current back to what circuit B would be as a 2057 Bulb?

I'm assuming the measured voltages were with the LED installed.
Image
95 SLE... a keeper. 241k miles. Low and Slow.
97 BMW 528i
98 Infiniti vq35'd i30: 13.3@104mph, 30MPG Hwy (RIP)
02 Jag X-type
03 BMW M5
05 Chevy Cobalt LS
07 Infiniti G35s 6MT (Sold)
07 Ducati Monster S2R 800 with DS1000 swap
83 Yamaha IT175K
72 Yamaha DS7: '74 RD250 swap, JL chambers

Info on dropping a 92-99: Here.
User avatar
J Wikoff
Administrator
Administrator
Posts: 17080
Joined: Mon May 19, 2008 7:01 pm
Year and Trim: 1992 SSE
2009 G8 GT
Location: Central Illinois
Contact:

Re: How to get switchback LEDs to work

Post by J Wikoff »

I think the parking lamp power and turn signal power comes from different paths. I think if I snip the parking lamp power circuit (pin A), the LED will work as intended. I think that will also set off the bulb monitor. I think I can fix that by putting in a resistor to ground on the snipped circuit. I think maybe putting a resistor inline with that circuit instead could also work. I think I need to look at my FSM.
Image
WHITE WHINE - 1992 SSE Supercharged 236.26 ci (.040 Over) 15.090 at 90.2 MPH on old engine w/ slipping trans & melted O2 sensor - Gen 3 M62 and matching TB, Gen 2 Pully, Zillamotorsports Ported LIM, YT 1.72 Roller Rockers, SII FPR & Injectors, Hypertech Thermomaster chip w/ 160 Thermo, TransGo Shift Kit, Infinity/Pioneer Speakers & a 10" Alpine Type R Sub, all the watts, 140 amp Alternator, Ricepipe CAI w/ heatshield, Pilot Angel Eye Foglights, Clear Corners, '02 17" Chrome Bent 5's, Magnaflow F-Body Muffler and Hi-flo Cat, Ceramic Coated Ported Exhaust Manifolds, Fan Override, Monroe Reflex struts, red calipers
2009 G8 GT - Sport Red Metallic, loaded, SOLO Axlebacks, Rotofab Intake, Tuned, autodim mirror, removed intake manifold cover, HSV GTS triple gauge pod, two tone red-hot shifter and HSV SuperSport steering wheel, GXP rear sway bar and diffuser, 3.45 diff and various Camaro suspension bits, LED Taillights
User avatar
CMNTMXR57
Certified Bonneville Nut
Certified Bonneville Nut
Posts: 5841
Joined: Wed May 13, 2009 10:45 pm
Year and Trim: 2006 STS-V, 2004 GTO, 2009 G8 GT
Location: CHICAGO

Re: How to get switchback LEDs to work

Post by CMNTMXR57 »

I've just quickly cycled the power switch for the light I have them on. I have switch backs in the fogs on the Caddy. A quick cycling of the fog light switch, switches them.
Image

Retired Bonneville Owner and former GM Tech:
2004 Pontiac Bonneville GXP: Black/Ebony *SOLD*

Summer Toys: Combined 827 RWHP / 877lb/ft RWTQ
2004 Pontiac GTO: Impulse Blue Metallic/Black/M6: lots 'o mods, 415 RWHP / 405lb/ft RWTQ!
2006 Cadillac STS-V: Light Platinum Metallic/Light Gray/A6 - Spectre CAI, Magnaflow exhaust, Speed Inc. tune, 412 RWHP / 472lb/ft RWTQ

Daily Drivers:
2019 Chrysler Pacifica Limited: Mommy's new RGC
2015 Chrysler Town & Country Limited Platinum: Kids new RGC
2011 Camaro SS
2009 Pontiac G8 GT: L76, Sport Red Metallic
2004 GMC Sierra 2500HD: Victory Red - 8.1L Big Block and Allison
2003 Chevrolet Suburban 2500: Doeskin Tan - 8.1L Big Block... RIP
1999 Chevrolet Suburban: Sunset Gold Metallic - RIP
Post Reply