As an owner of a 1995 Toyota Tacoma, I’ve experienced my fair share of electrical issues, particularly with the headlights. Over the years, I noticed my headlights weren’t as bright as they should be, and I was dealing with dim, flickering lights that weren’t just frustrating—they were also unsafe. After a lot of research, I decided to try the H4 Relay Harness Kit for my Tacoma, and it’s made a world of difference.Why I Chose This KitThe primary issue I faced with my truck’s headlights was the dreaded dual ground problem that many older vehicles, particularly Toyotas, tend to suffer from. This problem stems from the headlights drawing power directly from the stock wiring, which isn’t built to handle the higher current demand of modern, brighter bulbs. Over time, this can lead to dim lighting, flickering, or even failure of the headlight bulbs.The H4 Relay Harness Kit is designed to fix this issue by bypassing the stock wiring entirely, providing a direct, stronger power source from the battery to the headlights. I was looking for a solution that would not only improve the lighting but also prevent future electrical problems, and this kit seemed to be exactly what I needed.First ImpressionsWhen the kit arrived, I was impressed with how well it was packaged. The H6054 7x6 Polycarbonate Headlights were clear and seemed very durable. I was a little intimidated by the wiring aspect since I’m not the most mechanically inclined, but the instructions were straightforward, and I quickly realized I could handle the installation myself.The H4 relay harness itself is well-built, with high-quality wires and connectors that felt secure and sturdy. The dual ground fix was a major selling point, as it addressed the key issue that had been causing my problems in the first place.Installation ProcessThe installation was a bit time-consuming but not overly complicated. After removing my old headlights and stock wiring, I followed the step-by-step instructions to install the relay harness. The most important part was making sure I correctly connected the dual ground wires, which can sometimes be tricky if you’re unfamiliar with automotive electrical systems. I’d recommend taking your time to ensure everything is properly connected.Once the wiring was complete, I attached the new headlights, which fit my 1995 Tacoma perfectly. The connectors clicked into place with no issues, and the entire process took me about two hours.The ResultsAfter installation, I couldn’t believe the difference. The lights were significantly brighter, and they stayed steady with no flickering. The true benefit, however, was the reliability. With the relay bypassing the stock wiring and providing direct power from the battery, my headlights now operate with consistent brightness without the strain on the original system.Driving at night is now a much safer experience. The improvement in visibility is noticeable, and I no longer worry about my headlights failing or dimming during a long drive.Why This Kit WorksThe key to why the H4 Relay Harness Kit is so effective lies in its design. By sending the current directly to the headlights from the battery, it bypasses the weak stock wiring, which often struggles with higher currents. This avoids the common dual ground problem that leads to voltage drops and dim lights in older vehicles.Additionally, the polycarbonate headlights are tough, resistant to road debris, and maintain their clarity over time. Paired with the relay harness, they deliver a significant upgrade over my old, aging headlights.Final ThoughtsAs someone who’s not an expert in car modifications but loves keeping my truck in good working condition, the H4 Relay Harness Kit was a fantastic choice. It solved a major electrical issue and improved my night driving experience. If you’re dealing with dim or flickering headlights, especially in older Toyotas like mine, this kit will solve your problem.Rating: 5/5This kit delivered on every promise, and I’m thrilled with the results. Not only have I solved the dual ground problem, but I’ve also ensured that my headlights will continue to function reliably for the long haul. Highly recommend!

Super easy to install fixed the no power problem to my new led lights on an old 86 Toyota pickup truck. Looks good. Can see wat better at night

Vehicle: 1996 Jeep Cherokee ClassicOverview: My headlight switch failed because it provides power to the headlights high/low beams through a factory wiring harness which is underpowered. The factory wiring harness is also the culprit of your dim lights. In my case, the headlight switch burnt up leaving me with no lights.Solution: I replaced the faulty switch and decided to upgrade to the H4 wiring harness. The H4 harness re-routes power to the headlights from the switch to the battery making the lights much brighter and removing the electrical load from the switch (while the switch no longer powers the headlights it will still function as your headlight switch.)Installation notes: The H4 wiring harness is truly plug-and-play. The only additional components I used were self-tapping screws, a piece of sandpaper for cleaning up the locations where I terminated my grounds, standard electrical tape, and a few extra cable ties. The overall length of the harness was plenty long for me. There wasn’t a whole lot of extra space to mount the relays next to the battery but it was doable. Had I simply taken 5 minutes to remove the battery it would have been a breeze. Total install time was about 90 minutes.Results: Noticeably brighter OEM headlights. Happy headlight switch and your vehicle will be ready for H4 aftermarket LED headlights (which you’re going to eventually do anyway right?)The harness itself comes with an in-line 30-amp breaker for your battery hookup and 2-80 amp relays. As an electrician by trade, I was impressed with the overall product quality. The crimps were strong and secure. The only thing that concerns me about this entire project would be the fact that the relays are not water-proof which may be an issue for the 4x4 crowd who would much prefer driving through a creek than over it.Final note: There are great install videos on YouTube if you are new to these things. Even for a novice DIY project, trust me, this is as simple and straightforward as the reviews indicate. Last comment, terminate your grounds correctly. Years of experience as a sparky, it’s not the harness that’s not working it’s because you didn’t land your grounds right.

Super easy installation, clear instructions, anyone could do it in 5 minutes

1992 Isuzu Pickup: YOU NEED THESE for an LED upgrade. The little adapters that come with some of the headlights did not work for this application no matter what combination I tried. The moment I installed this, it worked instantly. Thankfully there was no resistor needed for the blue "brights" dash light to work as normal. I appreciated the person that noted this on their review but it wasn't necessary for this vehicle, although due to the warning of possibly needing it, was prepared to get one. Price was a Black Friday deal which was about 6 dollars off, but the quality of the wiring/resistors/ceramic connectors, I wouldn't think twice to purchase them at regular cost if necessary. Not sure that would have been the case if I didn't get them on sale because sometimes I'm cheap, but you deal with getting what you pay for when you're like that. Glad these were on sale. The wire length was about exact for my mini truck (think 90's S10 or Marty McFly's 4x4 Toyota for size). If the truck was any bigger, I may have been sweating for space. The wrap over the wiring that goes from one side to the other looks nice, it makes it appear like a factory harness. I recommend if you've got an ISUZU pickup between 88-92 (I can vouch for that due to my application)

If you have a vehicle with double ground switching (like my 2000 GMC Safari) and you want LED headlights this is what you need. Easy install and it works.

excelente producto, trabaja muy bien.

Easy install and good product

Arregló mi problema de solo luces bajas y voltaje ya que brillan más mis luces led y facilita el manejo de noche.

Works as it should.