LED Headlight with fog light issue... - ZR-1 Net Registry Forums

-=Jeff=- · 04-14-2019

Yeah, I know it has been posted and gone over several times.

BUT

Now time to post my solution I used on my 1990

**Disclaimer: Findings based on my 1990 and FSM, other years may vary**

In the FSM the shows that the Fog light relay grounds through the High Beam. When the high beams are activated in the OEM solution, 12v is applied on both sides of the coil for the relay which then causes the lights to turn off.

When we switch to LED, the high beam filament is replace with electronics, so that does not work so well. Most use resistors, which to me, still gives the load of a Halogen/ Filament light, yes it works, but I want the efficiency benefit.

I acquired a socket and relay from a donor harness I have, I added the relay to my harness to accomplish what I need. Here are the details:

Find the Fog Lamp relay. in my 1990 it is the furthest to the right under the dash.. Look for the Light Green wire. that is the wire you need to manipulate..

Unpin the LT GRN from the current relay move it to 86 of the added relay.

Pin a new wire in the spot where you removed the LT GRN (it is either 85 or 86), Pin the other end of this wire to 87a of your added relay.

On the added relay, Pin 30 and Pin 85 are both connected to ground.

Done, no wires cut, not relays tampered with. I have not installed LED Headlights just yet, but got the car ready for them. So this should work without issue. works fine with my current lights. I will be adding LED Headlights and LED Fog Lights soon.

Ccmano · 04-14-2019

Nice, mine will be in process tomorrow. Sounds like the most elegant solution yet.
H

XfireZ51 · 04-15-2019

I used a variation of Yun’s solution by cutting the relay leg connected to the lt grn wire and then soldering a wire to that cut down leg running it to a ground using as stud found halfway up alongside the door opening. The stud will be easier to see if u remove the side bezel for the fuse panel.

Ccmano · 04-15-2019

Relay location is Driver side or passenger side?
H

-=Jeff=- · 04-15-2019

Passenger side

XfireZ51 · 04-15-2019

FSM shows location incorrectly. Of the 4 relays there, its the one closest to the passenger door opening.

-=Jeff=- · 04-28-2019

to update.. the Mod I made works as expected (like factory) with LED Headlights and LED Fog Lights

Ccmano · 04-28-2019

Quote:

Originally Posted by -=Jeff=-

to update.. the Mod I made works as expected (like factory) with LED Headlights and LED Fog Lights

Agreed... mine too.
H

ghlkal · 05-06-2019

Quote:

Originally Posted by -=Jeff=-

Find the Fog Lamp relay. in my 1990 it is the furthest to the right under the dash.. Look for the Light Green wire. that is the wire you need to manipulate..

Unpin the LT GRN from the current relay move it to 86 of the added relay.

Pin a new wire in the spot where you removed the LT GRN (it is either 85 or 86), Pin the other end of this wire to 87a of your added relay.

On the added relay, Pin 30 and Pin 85 are both connected to ground.

Done, no wires cut, not relays tampered with.

Nice, thanks for posting this.

Bookmarked for when I get LED headlights ...

-=Jeff=- · 05-07-2019

Quote:

Originally Posted by ghlkal

Nice, thanks for posting this.

Bookmarked for when I get LED headlights ...

Want a set of LED headlights? PM Me. I have a set with maybe an hour of time on them. I need to remove them as they cause static on the FM of my Aftermarket Radio.. I also have the JDM Astar rear LED bulbs (caused the same issue for me)

I will be going back to my Halogens

04-14-2019	#1
-=Jeff=- Join Date: Jul 2007 Location: Bartlett, IL Posts: 7,165	LED Headlight with fog light issue... Yeah, I know it has been posted and gone over several times. BUT Now time to post my solution I used on my 1990 Disclaimer: Findings based on my 1990 and FSM, other years may vary In the FSM the shows that the Fog light relay grounds through the High Beam. When the high beams are activated in the OEM solution, 12v is applied on both sides of the coil for the relay which then causes the lights to turn off. When we switch to LED, the high beam filament is replace with electronics, so that does not work so well. Most use resistors, which to me, still gives the load of a Halogen/ Filament light, yes it works, but I want the efficiency benefit. I acquired a socket and relay from a donor harness I have, I added the relay to my harness to accomplish what I need. Here are the details: Find the Fog Lamp relay. in my 1990 it is the furthest to the right under the dash.. Look for the Light Green wire. that is the wire you need to manipulate.. Unpin the LT GRN from the current relay move it to 86 of the added relay. Pin a new wire in the spot where you removed the LT GRN (it is either 85 or 86), Pin the other end of this wire to 87a of your added relay. On the added relay, Pin 30 and Pin 85 are both connected to ground. Done, no wires cut, not relays tampered with. I have not installed LED Headlights just yet, but got the car ready for them. So this should work without issue. works fine with my current lights. I will be adding LED Headlights and LED Fog Lights soon. __________________ 1990 Corvette ZR-1 #1051 Watson Headers (2" Primary) - Flowmaster Cats - Borla Catback Late Model IH - Plenum Coilovers - 4.10s Custom Interior NCM Lifetime Member #978

04-14-2019	#2
Ccmano Join Date: Jun 2006 Location: Sparks, NV Posts: 2,852	Re: LED Headlight with fog light issue... Nice, mine will be in process tomorrow. Sounds like the most elegant solution yet. H __________________ 90'ZR-1 #1461 Red/Black Ported Intake, Degreed Cams, OBX Headers & Exhaust, Fidanza FW, Secondary Delete, Custom tune, C6 GS Wheels. Sold 08 C6 Z51 Crystal Red Metallic Sold Vararam Intake, Tune, Sold 05 C6 Z51 Red/Black Sold 90'ZR-1 #1723 Black/Gray Sold but not forgotten 91' Z51 L98 White Vert. My First, you always remember your first. Sold.

04-15-2019	#3
XfireZ51 Join Date: May 2007 Location: Chicagoland, IL Posts: 9,704	Re: LED Headlight with fog light issue... I used a variation of Yun’s solution by cutting the relay leg connected to the lt grn wire and then soldering a wire to that cut down leg running it to a ground using as stud found halfway up alongside the door opening. The stud will be easier to see if u remove the side bezel for the fuse panel. __________________ [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

04-15-2019	#4
Ccmano Join Date: Jun 2006 Location: Sparks, NV Posts: 2,852	Re: LED Headlight with fog light issue... Relay location is Driver side or passenger side? H __________________ 90'ZR-1 #1461 Red/Black Ported Intake, Degreed Cams, OBX Headers & Exhaust, Fidanza FW, Secondary Delete, Custom tune, C6 GS Wheels. Sold 08 C6 Z51 Crystal Red Metallic Sold Vararam Intake, Tune, Sold 05 C6 Z51 Red/Black Sold 90'ZR-1 #1723 Black/Gray Sold but not forgotten 91' Z51 L98 White Vert. My First, you always remember your first. Sold.

04-15-2019	#5
-=Jeff=- Join Date: Jul 2007 Location: Bartlett, IL Posts: 7,165	Re: LED Headlight with fog light issue... Passenger side __________________ 1990 Corvette ZR-1 #1051 Watson Headers (2" Primary) - Flowmaster Cats - Borla Catback Late Model IH - Plenum Coilovers - 4.10s Custom Interior NCM Lifetime Member #978

04-28-2019	#7
-=Jeff=- Join Date: Jul 2007 Location: Bartlett, IL Posts: 7,165	Re: LED Headlight with fog light issue... to update.. the Mod I made works as expected (like factory) with LED Headlights and LED Fog Lights __________________ 1990 Corvette ZR-1 #1051 Watson Headers (2" Primary) - Flowmaster Cats - Borla Catback Late Model IH - Plenum Coilovers - 4.10s Custom Interior NCM Lifetime Member #978