so i purchased ZC headlights and installed on my 88 hatch...so our oem headlight switch doesnt turn off low beams when we turn on highbeams while headlights are on, because of oem 9006/9005 headlight system. Is there something i can do so that my headlight switch can turn off lows when highs turn on? like how eg and ek headlight switches are? can i use eg or ek headlight switch? do i have to buy jdm headlight switch?

 

All you need to do is wire up a N/C relay into the power feed to the low beam. Feed the power from the high beam to the latch of the relay, and when power goes to the high beams, that same power will cut the feed to the low beams.

 

whats a n/c relay?

 

Normally closed. That means while the switching pole doesn't have current electricity flows to the load.

You'll have to get a 5 pole relay to get this to work since I have yet to see a normally closed 4 pole relay for sale at a parts store.

Here's a quick diagram and some stuff explaining it.

85 and 86 are your switching current. In the case of this diagram it doesn't matter which ones + and which ones -. Some relays have diodes on the coil and they do require a certain polarity.

30 is where you'll feed your 12vdc + into the relay, the wire that normally goes to the bulb, hook it up there.

87a is the normally closed contact, you'll run a wire from it to your low beam bulb

85 will be tapped from your high beam bulb. Splice a wire into the stock 12vdc + wire going to the high beam bulb. This is now the reference you have for the relay to switch when you turn on the high beams.

86 goes to ground

87 is unused in this application

 

most ef headlights stay on when the highbeams are on at least the 90-91. the egs i know have only a single dule filiment bulb. thats my favorit thing about my headlights.

 

This should be stickied and sir added to the title. it applies for the sir and Vt headlights as well.

 

so let me see if i got this straight...ive wired up 4 prong relays before, not sure if they have been N/C relays..normally 30 is constant voltage, 86 is ground, 85 has been the switch and 87 been the application. when 85 sends voltage to relay it creates continuity between 30 and 87.. so in an N/C relay, is 85 on all the time as long as 30 has constant voltage? and when you send voltage to 87 from hight beam(high beam) it cuts continuity between 30 and 85? ill wire it up like ur saying i just want to understand concept for future reference

 

and yea like i said i have the zc headlights which use an h4 bulb like the egs

 

and can a 4 prong relay be wired up the same? cuz i usually get my relays from autozone

 

Most 4 pole relays are normally open, meaning that until 85 has power no current flows to the load. I have never seen a 4 pole automotive relay that is normally closed.

In that N/C relay 87a has power all the time until 85 has power. Then power flows from 30 to 87.

I was thinking about another way to wire this up.

85 goes to your old high beam headlight wire
86 goes to ground
30 is fused power to the headlights
87A is your low beam headlight
87 is your high beam headlight

So, when low beams are on current flows through pole 30 into pole 87A, when you switch on the high beams (pole 85) the relay changes state sending power to the high beam filament through pole 87.

 

That sounds like it would work, but I think you'd have a brief instant with no lights as the relay switches poles. It migh be almost impercetible, but it would bug the s-h-i-t out of me.

 

Oh I see...so 87a is normally hot as long as 30 is hot....once 85 switches on, 87a is then open and 87 is closed right? Makes perfect sense. Thanks you guys. I read on other threads that mr78 at autoone is. A n/c relay

 

Did you ever get these wired up? About to start the same project and want to get the right relays.