LED headlight upgrade - Page 17 - ZR-1 Net Registry Forums

Paul Workman · 10-13-2017

Quote:

Originally Posted by XfireZ51

Just a question. Is there really a point to having fogs ON w the HI Beams?

Normally, the power for the fog light comes from the switch on the dash, through the fog light relay coil, then through the high beam filament to ground (and back to the battery via the chassis).

Between the fog light and the high beam filament is another (hot) wire connected to the high beam switch. When that high beam switch is closed, voltage is equal on BOTH sides of the fog light relay coil - NO difference in potential - and current through the relay coil stops and the fog light circuit opens. The path for high beam current comes directly from that high beam switch to the wire connected between the fog relay and the high beam filaments.

The substitution of an LED in place of the high beam filament changes the scheme significantly by increasing the resistance in the circuit significantly.

LEDs draw a tiny fraction of the current of their FILAMENT counterpart. And, their (forward direction) opposition to current flow (i.e., "impedance") is very low; so low that additional resistance or a current regulator is typically installed in series with the LED to allow it to work within its limited (current) parameters.

It is that current limiting additional resistance necessary for the LED that causes a problem for the fog lights. Where the headlight filament resistance may have been less than 10Ω to ground, the resistance in the LED path may be several 100s of ohms!

Solution: either install a (LOAD) resistor to ground with similar impedance as the original filament the LED replaced, OR provide a alternate path to ground for the fog light filament (relay).

LOAD resistor:

Restores the original control and functionality of the lights
Generates significant heat that has to be dissipated, when the high beams are on.
Adds external connections that are exposed to the outside environment

Alternate ground for the fog light relay:

Compared to the OE configuration, it reduces overall current draw when the high beams are ON
Results in the fog lights remaining ON along with the high beams*.

XfireZ51 · 10-13-2017

Paul,

My question had to do w the utility of having the fogs on while driving w Hi Beams. Does it really make a difference when driving?

secondchance · 10-13-2017

Another new LED headlight product that should work for our cars. At $54.99 each, a real bargain!

Anyone willing to experiment?

http://www.ebay.com/itm/1-Xprite-60W...ZZLzX-&vxp=mtr

GOLDCYLON · 10-13-2017

Quote:

Originally Posted by secondchance

Another new LED headlight product that should work for our cars. At $54.99 each, a real bargain!

Anyone willing to experiment?

http://www.ebay.com/itm/1-Xprite-60W...ZZLzX-&vxp=mtr

Not a fan of the Lighted LED LEGO in the DRL mode yikes ! I hope Hansen gets these again everything is on backorder currently. GC

-=Jeff=- · 10-24-2017

Roadster, I never really answered your question.. Look at Paul's post 4-5 above mine, talking about how the fog lights and headlights work. my thing was to move the wire and add a relay I posted back a few pages, this will then detect when the high beam is on and use the relay to open the fog light circuit, turning the fog lights off when the high beams are on. then when low beams are on, the fog lights are on.

My biggest thing was to remove the load, yes our cars are fine with the OEM load, but any load I can remove at night is better, I will do the Relay mod when I pull the dash pad this winter, as I am doing other things too. this will prep me for LED headlights.

Roadster · 10-24-2017

No problem Jeff......just went out to the garage and tested.......
Park lights on....fog lights will turn on or off....
Headlights on....fog lights will turn on or off....
High Beams on.....fog lights will not turn on with switch.....if fog lights are on with low beam and switched to high beam....fog lights will automatically turn off and come back on when switched back to low beam....
IMO with these new headlights.....I don't feel the need for the use of the fog lights when using the high beams anyway as these are very bright.....very satisfied with the purchase.....

-=Jeff=- · 10-24-2017

I forget did you buy genssi or Larsen?

Sent from my iPhone using ZR-1 Net Registry

Roadster · 10-24-2017

Quote:

Originally Posted by -=Jeff=-

I forget did you buy genssi or Larsen?

Sent from my iPhone using ZR-1 Net Registry

I went with Larsen.....again very satisfied.....and the resistor works great....no cutting into any wires.....worked well for me....

-=Jeff=- · 10-24-2017

Quote:

Originally Posted by Roadster

I went with Larsen.....again very satisfied.....and the relay works great....no cutting into any wires.....worked well for me....

relay or resistor?

just confirming, my relay solution either cuts or moves a wire

GOLDCYLON · 10-24-2017

I went with Larsen as well I used the plug in adapter that superbrightleds sells. My foglight do not work with the high beams on. However the light from the LEDs are so superior I'm not really sure if that its really a problem. Also I test fit one of the LED headlights without the adapter and both lights new and old worked like they should. Not even sure if I needed it Jeff

10-13-2017	#162
XfireZ51 Join Date: May 2007 Location: Chicagoland, IL Posts: 9,669	Re: LED headlight upgrade Paul, My question had to do w the utility of having the fogs on while driving w Hi Beams. Does it really make a difference when driving? __________________ [SIGPIC][/SIGPIC]Former Membership Chairman Former ZR-1 Registry - BOD 1972 Corvette 4speed base Coupe SOLD long time ago 1984 Corvette Z-51/4+3 SOLD 1992 Corvette ZR-1 Aqua/Gray #474 SOLD 1992 Corvette ZR-1 Black Rose/Cognac #458 2014 Honda VFR Interceptor DX

10-13-2017	#163
secondchance Join Date: Aug 2006 Location: McLean, VA Posts: 3,705	Re: LED headlight upgrade Another new LED headlight product that should work for our cars. At $54.99 each, a real bargain! Anyone willing to experiment? http://www.ebay.com/itm/1-Xprite-60W...ZZLzX-&vxp=mtr

10-24-2017	#165
-=Jeff=- Join Date: Jul 2007 Location: Bartlett, IL Posts: 7,137	Re: LED headlight upgrade Roadster, I never really answered your question.. Look at Paul's post 4-5 above mine, talking about how the fog lights and headlights work. my thing was to move the wire and add a relay I posted back a few pages, this will then detect when the high beam is on and use the relay to open the fog light circuit, turning the fog lights off when the high beams are on. then when low beams are on, the fog lights are on. My biggest thing was to remove the load, yes our cars are fine with the OEM load, but any load I can remove at night is better, I will do the Relay mod when I pull the dash pad this winter, as I am doing other things too. this will prep me for LED headlights. __________________ 1990 Corvette ZR-1 #1051 Watson Headers (2" Primary) - 3" Magnaflow Bullet cats - LT4 Catback Late Model IH - Plenum Coilovers - 4.10s Custom Interior NCM Lifetime Member #978

10-24-2017	#166
Roadster Join Date: Mar 2014 Location: Warrington PA Posts: 1,913	Re: LED headlight upgrade No problem Jeff......just went out to the garage and tested....... Park lights on....fog lights will turn on or off.... Headlights on....fog lights will turn on or off.... High Beams on.....fog lights will not turn on with switch.....if fog lights are on with low beam and switched to high beam....fog lights will automatically turn off and come back on when switched back to low beam.... IMO with these new headlights.....I don't feel the need for the use of the fog lights when using the high beams anyway as these are very bright.....very satisfied with the purchase..... __________________ Tom 1994 ZR-1 #009 "captured test fleet car" 1974 LS4 454 Vert 1982 L83 CFI...now a retired "dd"....Sold WAZOO Member Last edited by Roadster; 10-24-2017 at 08:26 PM.

10-24-2017	#167
-=Jeff=- Join Date: Jul 2007 Location: Bartlett, IL Posts: 7,137	Re: LED headlight upgrade I forget did you buy genssi or Larsen? Sent from my iPhone using ZR-1 Net Registry __________________ 1990 Corvette ZR-1 #1051 Watson Headers (2" Primary) - 3" Magnaflow Bullet cats - LT4 Catback Late Model IH - Plenum Coilovers - 4.10s Custom Interior NCM Lifetime Member #978

10-24-2017	#170
GOLDCYLON Join Date: May 2007 Location: Peoria, AZ Posts: 9,153	Re: LED headlight upgrade I went with Larsen as well I used the plug in adapter that superbrightleds sells. My foglight do not work with the high beams on. However the light from the LEDs are so superior I'm not really sure if that its really a problem. Also I test fit one of the LED headlights without the adapter and both lights new and old worked like they should. Not even sure if I needed it Jeff __________________ GOLDCYLON - 91 ZR-1 #2014 GOLDCYLON - 90 ZR-1 #2794, 4L60e (Formerly Schrade's) GOLDCYLON - 11 CTS-V Arizona State Director 91 WHITE/BLACK #2014. 380 P&P&PCed,Ported Heads, Jeal Long tubes, Corsa Exhaust/FIKSE FM-5s /LED TLs, LED Headlights, Front Wilwood 6 piston narrowlite calipers and rear Wilwood caliper street shop mod,CNCed Coolant Pipes,TPI Cvr,Filter cover,Stainless Bolts, DRM/DOM PROM /ZFDOC mod build #102,DRLs,BMAD with stainless Debris Screen,Coplan Air Blaster, Pioneer APP Radio 4,Brey-Krause HB,Sub Bar,Fire extinguisher seat mount,DRM Coilovers,LEDs everywhere,Compass mirror (orange),V1 DIC hidden display, Homelink sun visor, Carbon Fiber top x3 and APSIS Carbon Fiber interior, APSIS CF Steering Wheel/NAPA Leather, Banski trailing arms, Guldstrand front suspension,urethane bushings from Prothane (total suspension) ZFDoc drive shaft safety loop, raptor shift light (orange),AO engineering louver front plate, Console seat cushion, 96CE seats with black custom Sheepskins, ss billet catch can,Viper remote entry/alarm,Cragar Rear Louvers,LED side louver lights, Dewitts Radiator with SPAL fans and a Woods 160 T-Stat 90 RED/BLACK #2794. 4L60e Automatic Stage V by RPM Transmission, TCI Dedicated TCM, OBX Stainless Headers, Corsa Exhaust, SAN Secondaries and Haibeck PROM, Exotic Muscle Coil overs, LED Interior Lights, LED Tail Lights, LED Headlights, 94 Sport seats with black custom Sheepskins , Cragar rear louvers, GS Front calipers, Banski Trailing arms, APSIS Carbon Fiber steering wheel, Front and Rear Baer Eradispeeds, DRLs, Guldstrand front suspension,urethane bushings from Prothane (total suspension), Dewitt's Raditor with Dual SPAL fans and a Haibeck 170 T-Stat 11 RED/GREY CTS-V Last edited by GOLDCYLON; 10-24-2017 at 10:42 PM.