ZR-1 Net Registry Forums  

Go Back   ZR-1 Net Registry Forums > C4 ZR-1 > C4 ZR-1 Technical Postings

Reply
 
Thread Tools Display Modes
Old 04-14-2019   #1
-=Jeff=-
 
-=Jeff=-'s Avatar
 
Join Date: Jul 2007
Location: Bartlett, IL
Posts: 7,157
Default 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
Shelby Series 1 - Wilwood Brakes
Custom Interior
NCM Lifetime Member #978
-=Jeff=- is offline   Reply With Quote
Old 04-14-2019   #2
Ccmano
 
Join Date: Jun 2006
Location: Sparks, NV
Posts: 2,843
Default Re: LED Headlight with fog light issue...

Nice, mine will be in process tomorrow. Sounds like the most elegant solution yet.
H
Ccmano is offline   Reply With Quote
Old 04-15-2019   #3
XfireZ51
 
Join Date: May 2007
Location: Chicagoland, IL
Posts: 9,685
Default 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.
XfireZ51 is offline   Reply With Quote
Old 04-15-2019   #4
Ccmano
 
Join Date: Jun 2006
Location: Sparks, NV
Posts: 2,843
Default Re: LED Headlight with fog light issue...

Relay location is Driver side or passenger side?
H
Ccmano is offline   Reply With Quote
Old 04-15-2019   #5
-=Jeff=-
 
-=Jeff=-'s Avatar
 
Join Date: Jul 2007
Location: Bartlett, IL
Posts: 7,157
Default 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
Shelby Series 1 - Wilwood Brakes
Custom Interior
NCM Lifetime Member #978
-=Jeff=- is offline   Reply With Quote
Old 04-15-2019   #6
XfireZ51
 
Join Date: May 2007
Location: Chicagoland, IL
Posts: 9,685
Default Re: LED Headlight with fog light issue...

FSM shows location incorrectly. Of the 4 relays there, its the one closest to the passenger door opening.
XfireZ51 is offline   Reply With Quote
Old 04-28-2019   #7
-=Jeff=-
 
-=Jeff=-'s Avatar
 
Join Date: Jul 2007
Location: Bartlett, IL
Posts: 7,157
Default 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
Shelby Series 1 - Wilwood Brakes
Custom Interior
NCM Lifetime Member #978
-=Jeff=- is offline   Reply With Quote
Old 04-28-2019   #8
Ccmano
 
Join Date: Jun 2006
Location: Sparks, NV
Posts: 2,843
Default Re: LED Headlight with fog light issue...

Quote:
Originally Posted by -=Jeff=- View Post
to update.. the Mod I made works as expected (like factory) with LED Headlights and LED Fog Lights
Agreed... mine too.
H
Ccmano is offline   Reply With Quote
Old 05-06-2019   #9
ghlkal
 
ghlkal's Avatar
 
Join Date: Jan 2012
Location: Wisconsin
Posts: 885
Default Re: LED Headlight with fog light issue...

Quote:
Originally Posted by -=Jeff=- View Post
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 ...
__________________
1990 ZR-1 #2180 Red/Black
Many of the usual mods for 460HP, tuned by Marc Haibeck
ZR-1 Net Registry Member #1548
ghlkal is offline   Reply With Quote
Old 05-06-2019   #10
-=Jeff=-
 
-=Jeff=-'s Avatar
 
Join Date: Jul 2007
Location: Bartlett, IL
Posts: 7,157
Default Re: LED Headlight with fog light issue...

Quote:
Originally Posted by ghlkal View Post
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
__________________
1990 Corvette ZR-1 #1051
Watson Headers (2" Primary) - Flowmaster Cats - Borla Catback
Late Model IH - Plenum
Coilovers - 4.10s
Shelby Series 1 - Wilwood Brakes
Custom Interior
NCM Lifetime Member #978
-=Jeff=- is offline   Reply With Quote
Reply


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 05:59 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2025, vBulletin Solutions Inc.
Copyright ZR-1 Net Registry 2025