Headlight wiring help needed.

[white90esex]

Anyone have some first hand experience?

Im not a very electrically inclined person and just realized the two different style headlamps use different bulbs. Some sorta cut/splice is probably needed but I honestly don't know where to begin.


94-96 Q45 Low is an H4.



90-93 is a 9006 which is a 2 prong plug. Im just wondering what the heck to do to wire them correctly.

[Infinitiguy19]

I think you will have to swap all four doors and rear bumper because of the moulding. Why do you want a 1994 Q45 front end? You relize the 1994-1996 Q45's have fog lamps and you will need a switch to activate them. JDM switches for the 1990-1993 Q45's are hard to come by.

[white90esex]

I already swapped the front end. Hood, fenders, bumper, and lights. The car was hit in a parking lot and messed up everything else. Q45 parts are nearly impossible to come by in CO. You don't need to swap doors or rear bumper. You can just use the side moldings off of them, no need to swap a whole door for a small piece that is adhered to the vehicle right?

Anyway, yeah I'm terrible at wiring...

the 94 headlight uses an H4 for the low beam and 9005 for the high.
the 90 headlight uses a 9006 for the lob beam and 9005 for the high.

The 9006 is a two wire plug, the H4 is a 3 wire.


so yeah. Any help?

[white90esex]

So I think I have a solution.

I will attach the ground and the power of the 9006 to the h4's ground and low beam prongs. I will then plug the high beam (9005) into where it needs to go. Then off of the positive of the 9005 I will run a wire to the H4 high beam prong.

By doing this I will get at low beam just the single H4 low beam, when the high is hit the H4 will ignite its second filament PLUS the 9005 high beam bulb will come on as well.

Sound correct? I think it will work the way it should?

[Infinitiguy19]

If I were you and had the oppertunity to mess with the wiring for the lights I would do this: http://www.danielsternlighting.com/tech ... elays.html

But who know if the Q is'nt already as good as it comes as far as lighting goes? I never looked into it really but no doubt Qship96 has more experince.

Is there no way to make 1990-1993 Q45 headlight bulbs fit into the 1994-1996 Q45 headlights?

[qship96]

So I think I have a solution.

I will attach the ground and the power of the 9006 to the h4's ground and low beam prongs. I will then plug the high beam (9005) into where it needs to go. Then off of the positive of the 9005 I will run a wire to the H4 high beam prong.

By doing this I will get at low beam just the single H4 low beam, when the high is hit the H4 will ignite its second filament PLUS the 9005 high beam bulb will come on as well.

Sound correct? I think it will work the way it should?

Will it work? In theory,the electrical path you describe would certainly get the power to the correct filaments based on whether you choose low or high beam operation from the interior stalk.The real issue will be can the small wiring Nissan chose to use throughout the entire lighting circuit handle the 2x increase in wattage you will now impose on it during high beam operation without a meltdown, or more likely just a large voltage drop decreasing bulb output significantly.
Paul was on the right track with his link to installing a heavy duty headlamp wiring harness,and the link he provided contains more solid,accurate advice regarding automotive lighting than can be found anywhere in the world.If you want to do it right,and gain maximum performance from your lighting,a custom harness is essential.

If you do not want to go through the hassle of building your own harness from the info provided in your link, call Ray at Susquehanna Motorsports and discuss your needs with him......for about $120 or so, he will custom make you a harness using ultra heavy duty wiring and relays that will be a plug and play installation and provide enough capacity to almost power a welder off of...........certainly will provide much better illumination {due to correcting voltage drop} from stock wattage bulbs, and allow you to seriously upgrade bulbs to much higher wattage in the future if you desire high performance lighting............Rays harness is truly a work of art, you can tell he enjoys building them from the attention of detail he puts into every inch of the product......highly,highly recommended.

[white90esex]

Ahhh. Yes I will have to read that, looks informative.


On the 90-93 headlights when the high beams are turned on does it keep the low beam on as well or does it only turn on the high. If thats the case I may just run it so that when the highs are turned on the low will stay on as low and the high will turn on. I rarely use high beams so idk... Lots of options