Hi/Lo Relay Wire Harness

Bi-xenon Relay: MotoControl (9007/9004)



[ In Stock: 584 pieces ]


Product Details

Reality Check: Customers often ask, Do I really need a harness? Yes! A relay harness is designed to deliver steady voltage to your HID ballasts directly from the car battery. Nobody likes a flickering headlight, so why risk it? Factory headlight outputs are really only designed to power a halogen light bub, not an HID ballast.

Under Control: Morimoto makes it easy with the MotoControl 9004/9007 Bi-Xenon relay harness. Designed to be completely plug-n-play; it's a seamless solution to keep your low and high beams under control with the original stalk inside the car. Works perfectly with Bi-xenon projector retrofits and Hi/Lo HID systems.

Advanced: The third generation MotoControl 8-Pin Relay has a tiny built-in capacitor that stores and releases it's charge between mode changes. So even if there's a short gap between the low and high beam signals from your car, your HID's will run smoothly. It's sealed weather-pack connector is new for 2014 and is a major reliability upgrade compared to other bi-xenon harnesses.

Universal: This harness is designed to work with both positive and ground switched headlight circuits, making it universally compatible with all vehicles no matter new or old.

Plug n Play: The layout of the harness makes it easy to install. With just a few simple connections, even your mom could set this thing up! Wire lengths are long enough to be used in everything from compact cars to SUVs and it's designed to be 100% plug and play (no cutting or splicing needed).

OEM Grade: Aside from being ahead of the game from a technical standpoint, the HD relay is also a work of art. With it's wiring protected by abrasion resistant Techflex mesh sleeving and it's extruded aluminum relay shell that's been anodized and laser engraved - the MotoControl Harness will look factory fresh under the hood!

Trusted: For more than a decade, we've worked hard to earn our killer reputation. Car guys world-wide know that our shop carries the internet's best selection of high performance automotive and powersport lighting products at the best prices, and we've got the best, most knowledgeable team of real enthusiasts to help back it up. If we sell it, then you bet we've put it to the test on our own cars, trucks, and bikes. Need a recommendation on parts for your project? Got a tech question? Wholesale inquiry? Contact us!

Product Specs

  • What's Included

  • RELAY HARNESS: 1x Morimoto 9004/9007 Bi-Xenon

  • RELAY: 1x Silver WeatherPack MotoControl Low/High

  • WARRANTY: 2 Years

  • NOTE: One Harness Controls Both Headlights

  • Compatibility


  • HID SYSTEMS: Low Beams, High Beams, or Fog Lights

  • BI-XENON PROJECTORS?: You'll need High Beam Splitters

  • PWM PULSING SIGNAL?: You'll need a Capacitor Link

  • CANBUS SYSTEM?: Use Standalone Canbus or the Mopar Spec harnesses

  • Tech Specs

  • INPUT TRIGGER: 1x 9007 Male

  • BALLAST OUTPUTS: 2x 9006 Female

  • HIGH BEAM OUTPUTS: 2x 9006 Female

  • GROUNDS: 2x Nickel-Plated Ring-Type

  • 12V POWER: 1x Nickel-Plated Ring-Type

  • FUSE: Inline 25A

Product Reviews

4.3 out of 5 stars

9 Reviews   Write a Review

5 out of 5 stars

2003 Mustang Cobra and MotoControl Bi-Xenon: 9007/9004

Lane Butler

First I have to commend the technical support staff. If I had contacted them before ordering I would not have had any issues. The relay kit is excellent quality and well put together. I installed on the passenger side of my car and noted three improvements that could easily be added: the power lead could be longer for installing away from the battery side, a cap should be added to cover the factory headlight plug that is not used, and pigtails to connect the high-beam leads would have saved a lot of time hunting and ordering. Also note that the high and low beam pins have to be swapped for proper function in my car. My only complaint is that these lights make my driving lights look terrible so now I have to upgrade them too!

5 out of 5 stars

Top notch service


My first faulty motocontrol box for a 01 mustang (9007) was quickly replaced by the excellent customer service. The only issue I had was figuring out the three signal wires from the box. Nonetheless, great quality product and very easy to install. Tip: ensure clean grounds and secure connections, and test headlight plug wires first to ensure proper install. Thanks a lot TRS!

4 out of 5 stars

Works but...

jesse cervene

Harness came with 2 wires in wrong location. Had to swap the ground wire and low beam wire to make work properly. Otherwise its running now and works perfect!

4 out of 5 stars

Overall build quality looks...

Jeffrey Lavin

Overall build quality looks good. Would recommend a cold weather rated insulation for wires. This is advertised as plug and play for 9004 and 9007 wiring. I found that NOT to be the case. I have 9007 wiring, I plugged it in to find that only the low beam was working. The high beam indicator on my dash was lighting up for both high and low beam. I measured the voltage at the 9006 plug going to the bi-xenon solenoid and it was -13v on both wires on one plug and +3v on the other plug.

Knowing that 9004 and 9007 plugs are the same except the ground and the low beam wire are switched, I swapped these two wires on the plug and then the high/low functionality worked perfect with battery voltage and ground at each 9006 plug and the dash high beam indicator then worked correctly.

4 out of 5 stars

Great Harness


Works flawlessly. only gripe is the lack of wiring diagrams for 9004 vs 9007. Had to re-pin the harness to the 9007 wiring. But the high beam circuit worked perfectly after i fixed the pins.

3 out of 5 stars

Cannot recommend

Michael Wood

The good: Connectors are good quality, wiring is good, wire loom looks nice, and the relay unit is small.

The bad: the relay unit is small. In an effort to make these more appealing, these are manufactured with small relays, that are much less reliable in my experience. When it's warm outside, this thing works fine. But, when colder, if the relay unit isn't mounted perfectly vertical (mine was mounted at about a 45 degree angle), the relays failed to fire both headlights about 75% of the time below 40 degrees Fahrenheit. I changed the position of the relay unit and reduced the failure rate to about 25%, but this is simply not acceptable. I can manage this when in a parking lot by turning the lights off and one, and tapping the relay unit, but I cannot have failures to start both headlights on the road. I will likely cut the relay unit off and replace with a couple of larger relays I have on hand, that don't care if they are on a vertical surface.

4 out of 5 stars

9004 and 9007 Are Not Pinned The Same...Install Guide Needs Updating

Marc Hichens

The harness is of high quality and works great! The braided sleeve, shrink tubing, and weather proof relay connector are excellent.

My Customer Service experience at TRS has always been outstanding.

However, the Install Guide is lacking with regard to repinning the connector for 9004 vs. 9007. The wire colors, as pinned right out of the package, matched the colors on my existing no-name 9004 relay harness, but the Morimoto harness didn't work properly as pinned. Out of the box, the high beam operated when the headlight switch was in the low beam position, and when the switch was in the high beam position, the low beam was enabled. The Install Guide shows a single pin-out for 9004 and 9007, which is incorrect. The Install Guide also describes swapping the Blue and White wires for a condition I was not experiencing (low beam works, but high beam doesn't work) and did not solve my problem. The picture to the left shows an H4 plug with arrows describing to swap the Brown and Blue wires, with no explanation as to why; swapping those wires did not fix my problem. In order to solve my problem, I had to swap the Brown and White wires to work with my car's 9004 harness. I would have expected such a resolution should have been included in the Install Guide.

Suggestions for Improvement:

* I suggest Morimoto update the Install Guide to be made more clear regarding how to ensure the harness is properly pinned for 9004 or 9007.

* I suggest Morimoto revise these harnesses to use a single Ground wire instead of 2 short pigtails (or provide as an option). The single Ground wire could be connected to the engine block or directly to the battery more conveniently than looking for 2 good Ground connections that might not turn out to be good Ground locations. I modified my harness to connect the 2 Grounds and run a single Ground to the engine block near where the battery connects to the block.

5 out of 5 stars

easy install


First time dealing with TRS,and I must say after purchasing the 9007/9004 Morimoto MOTOCONTROL BIXENON harness along with 9006 Male Pigtail for my bixenon projectors, were both easy to hook up,& I'm thoroughly impressed with the build quality of these products!!,and after having some trouble with the wiring (on my part)a quick response from customer service with what I needed to know to finish the job right

5 out of 5 stars

Awesome product


Ordered this harness for my Juke Nismo mini H1 retrofit. Had to change the pin configuration from 9004 to 9007. Works perfectly and made my install look very clean and professional, especially with braided sleeves on all the cables. No flickering when switching between low and high beam, capacitor does its job very well. Cable lengths were long enough for both sides. Can't complain about the pricing either. Shipping to Canada was reasonable and very fast. Thanks TRS!