Brighter Aftermarket Headlamps

[Hib Halverson]

Originally Posted by nelson007

Hello Hib,
Check your email for the weight of the Cebies. I emailed it to you a couple of weeks ago, i think the weight of one of them was 1lb &13oz.
Nelson007

Somehow that email got lost. Glenn weighed the ones I sent him so I used that number but I'll go back and add yours.

[g35c6mt]

Hello Hib,

I just ordered and installed these on my '94 ZR-1. Fantastic upgrade. Thank you for the recommendation. I ran into the driving lights/ground issue though (they no longer turn on and the button activates the high beams instead).

Any ideas on how to correct this would be greatly appreciated. Thanks!

[Hib Halverson]

Not sure what you mean. A ZR-1 has no driving lights unless you installed aftermarket aux. lighting.

Are you talking about your fog lights or maybe the parking lights?

[g35c6mt]

I meant the fog lights. Im reading elsewhere the solution is to directly ground the fog lights to the chassis. Will this work?

[Hib Halverson]

Oh crap. I feel like an idiot. Some will say, "If you feel like an idiot, you are an idiot".

Turns out, "G35c6mt", is correct. When you install those LED headlights, the fog lights no longer work. If the headlights are on and you turn the fogs on, the headlights go to high beam. If the parking lights are on and you turn on the fog lights, the fog lights and the headlights flicker.

I never tested the fog lights because 1) I've never used them because they so crappy and 2) I looked at the wiring diagram and noted that 91-95 is different than 90 and figured that would allow the fogs to work.

Once again, I should not have made that assumption.

As to how to fix the problem...
(sigh)
....it looks like just grounding the fog lights is not the solution because they are already grounded at G115 and G116. It's the fog light relay wiring that's the key.

[Hib Halverson]

After studying the FSM, I think the fix is to cut the Lt. Grn wire between the fog lamp relay pin D2 and splice S208 then ground the wire from fog lamp relay pin D2, but I need to test this.

With the stock fog lamp wiring intact, if you have fog lights on and the parking lights on or you have the headlamps on and the low-beam selected with the multifunction switch, current flows from the headlamp switch though the fog lamp relay's control side, though the high beam harness and to ground, then the fog lamps light up.

If you have the fog lights on and the high-beam selected, the voltage on both sides of the fog lamp relay control coil is the same so no current flows though the relay and the fog lamps go off.

Because the Nighthawks replace incandescent bulbs with electronics part of which is an LED, proper grounding though the high beam harness is not possible, so when the parking lights or low beams are on and the fog lamp switch is on, the high beams come on and the fog lights go off. This is also why when the parking lights are on and the fog lamp switch is on, the fogs and high beams either flicker or the fog lights are on and the high-beams flicker.

In any event, I need to test a fix.

[secondchance]

Hib,

There are internet posts regarding some LED bulbs interfering with radio signal. Did you notice any radio issue while testing LED headlights?

[-=Jeff=-]

So on the 1990-later cars there are a couple things:

There is a LT GRN wire that controls the High beam as well as the relay to the Foglights.

When the High beam is off, this wire is low (no voltage applied) and it uses the ground through the high beam. Which in the OEM case is a filament.. or a short if you will directly to ground on the other side of the Headlight. When the High beam is activated +12v is applied to the Lt Grn wire so now both sides of the Relay coil for the Fog Lights is at +12v so the coil it not activated.

The LED Headlight is probably not as basic as an LED and Resistor, I am guessing there is some electronics in the headlight module. So now when the High beam is on the circuit 'works' as it should. when on low beam, I am thinking there is now NO 'short' through the headlight to turn on the fog lights

the Simple fix is cut the LT GRN wire on the relay and tie it to ground, but the foglights will work for both HIGH/LOW beams.. to keep them working correctly, I am thinking another relay would need to be wired..

I am pretty sure I know how to get it in there, but I don't have the LED lights to test it..

One added relay:
Cut Lt Grn
Power side of Lt Grn to Pin 86 of Relay
Pin 85 and Pin 30 of relay to Ground (New Wire)
fog light side of LT Grn to 87a.

That should allow you to keep the correct functionality with minimum wiring and wire cuts

[Hib Halverson]

Originally Posted by secondchance

Hib,

There are internet posts regarding some LED bulbs interfering with radio signal. Did you notice any radio issue while testing LED headlights?

Actually, that is one thing I DID test and I noted no problems with the LED headlamps and the sound system.

As for the fix "-=Jeff=-" suggests above, that is my theory as well. I have not tested it as yet, however, because right now my ZR1 is stuck in my shop, parked in a location and manner that won't allow me to get the passenger side door open. I have to get in that way to get to where the fog light relay is located. I'm going to ground that green wire and road test.

[-=Jeff=-]

Originally Posted by Hib Halverson

Actually, that is one thing I DID test and I noted no problems with the LED headlamps and the sound system.

As for the fix "-=Jeff=-" suggests above, that is my theory as well. I have not tested it as yet, however, because right now my ZR1 is stuck in my shop, parked in a location and manner that won't allow me to get the passenger side door open. I have to get in that way to get to where the fog light relay is located. I'm going to ground that green wire and road test.

I might do that Mod just because.. (Honestly I think I have another issue I have to correct) and that might help