Last updated on July 4th, 2021 at 10:04 am

A few years ago, high-intensity discharge (HID) headlights became all the rage. The new design provides better light quality and quantity with a significantly longer lifespan. As soon as aftermarket kits hit the streets, people began shoehorning HID systems into cars that were not designed for these lights, resulting in numerous problems and tons of disinformation.

Aftermarket HID systems are the frequent target of ire from drivers all over the world. They tend to shine directly into opposing lanes, blinding drivers or jiggle around like they are mounted on jello. Numerous other problems arise that include flickering lights, bulbs that intermittently work, or systems that simply stop working all together for no apparent reason.

The level of frustration out there from drivers and installers dealing with the common problems of aftermarket HID light kits means that lots of solutions have been put forward. Some of the DIY solutions to HID troubleshooting work, others are not so helpful. We put together this troubleshooting guide to help the average DIYer or installer who is addressing problems or wants to install an HID headlight system while avoiding common mistakes that lead to trouble.

Common Issues with Previously Installed and Working Systems

One of the challenges with HID lights is when you purchase a car that someone else installed HID lights in but it did not originally come with the system. Often, a system will work fine at first, then fail and finding the problem is more difficult because you don’t know how the lights were installed and whether the wiring was done correctly. Chasing electrical gremlins is no one's favorite task, but it is essential to solving the most common problems.

Intermittent Function of Aftermarket HID Headlights

The most likely culprit is improper wiring connections. There are several mistakes that are common when doing most electrical upgrades, including HID headlight systems. Poorly crimped connectors frequently lead to intermittent function of one or both headlamps.

  • Flickering: Typically the result of poor connections.
  • Intermittent function: Also likely to be poor connections, but may include bad ballasts.
  • Only one side works: In a properly installed system, one side not working is most often the result of a bad bulb or ballast.

Ground Connection Problems

The first place to investigate is the ground connection. This should be firmly attached to a structural metal portion of the vehicle. A mistake that is often made is when installers fail to remove paint, rust, and dirt from the ground connection point. You should use a wire brush, grinder, or sandpaper to remove anything on the surface until you have clean, shiny metal. Apply a thin film of dielectric grease to the surface to prevent rust and encourage a good ground before reinstalling the bolt or screw.

Some installers tap into an existing ground wire rather than modify the vehicle to accept a new ground connection for the headlights. Sometimes, this approach works just fine but not always. Factory ground wires may attach to several different devices in the vehicle before making their way to ground, leaving the technician with lots of opportunities for poor ground connections that affect headlight performance.

Improper Crimping

Once you eliminate ground connection problems, you will need to investigate the other connections. The particular HID headlamp setup will have at least one power connection that typically uses the factory power wiring for the headlights. When installers must remove factory plug terminals and install aftermarket ones, the opportunity for problems increases.

There are a couple ways you can test for problems with connections. The first is simply to gently tug on the wire while holding the conector. If it pulls free, the connection is not good. Loose, poorly formed crimp connectors account for many of the intermittent light issues, including flickering lights.

Always use a good-quality crimping tool to form proper connections. It’s a good idea to use shrink-protect connectors with the HID headlight system to prevent dust and moisture from causing corrosion. Power to the headlight circuit should always route to the positive side of the vehicle battery, not jumpered to other accessories.

Using Resistance to Test the Circuit

You can use an ohmmeter to determine if a wire has a bad connection. Connect one lead to one connector and the other lead to the opposite connector end. You should have a resistance reading that indicates the circuit is complete. If you get infinite resistance you know there is either a poor connection or a compromised wire. First check both connection ends for secure crimps before tracing the wire in search of burns and cuts.

Bouncing, Jiggling HID Headlights

This is the most irritating issue to solve and it’s almost universal when installing aftermarket HID headlights. The main issue involves the difference in the manner of which headlight housings are made. Halogen headlights use a lightweight reflector to direct light from the bulb. Many modern cars use small electric motors to automatically level and stabilize the beam of light. The problem is that HID headlight projectors weigh significantly more than the original assembly. Factory self-levelers simply can’t take the weight of the HID assembly, causing the suspension to fail.

Solving this problem can be relatively simple or complex depending on the design of the original equipment. Your best bet is to find a manner of mounting the HID light so that it is secure. This will reduce bouncing and jiggling. The key is finding a spot on the vehicle that you can mount straps, brackets, or some other mounting system to eliminate the auto-levelers. You will need to incorporate a method of manually adjusting the beam.

Tips and Considerations if You Are Planning a DIY Install

One of the very first considerations you’ll want to make is whether installing HID headlights will be worth the expense. You need to keep in mind that aftermarket HID headlight systems are not legal for use on street vehicles as headlights in the United States. That means you can get a fix-it ticket if a police officer knows your vehicle didn’t come from the factory with HID headlights. Use HID headlights at your own risk and keep in mind that you may have to remove the HID system and return the vehicle to stock condition at any time. Aftermarket HID headlights depreciate the value of a vehicle for this reason.

Most of the worst problems with HID headlight kits on the market come from poorly executed installations. Many people skip important steps or components, leaving their vehicle with a partially functioning headlight system that is worse than the original halogen system. Before you buy an aftermarket headlight kit, you’ll want to plan on getting all of the important parts you’ll need.

Differences in Quality

One of the very first things you’ll notice when shopping HID systems is the wide variation in prices. There are three elements of any HID system that are key. First, you need high-quality bulbs. Cheap bulbs often fit poorly in the connectors, causing unacceptable amounts of bounce. Companies making cheap bulbs will use less-expensive gas mixtures in the bulbs, poorly fitting o-rings, and brittle plastic parts that can lead to dozens of common problems from short lifespan to weird colors.

The ballast is the most important component of the system. Cheap ballasts lack waterproofing and are bulky making installation a challenge. Ballast problems can cause flickering, lack of function, and can burn out your bulbs. Cheap ballasts run much hotter and produce less stable electrical outputs. Save yourself the trouble and expense and buy high-quality ballasts off the bat.

The type and quality of the HID light controller is also important. There are two types of controllers; CPU-based and ASIC-based. CPU controllers are considerably less expensive but often suffer from inferior components that lead to flickering and other visual problems as the power supply isn’t well regulated. ASIC controllers are expensive, but provide stable performance when properly installed. DO yourself a favor and start out with an ASIC controller.

Wiring kits supplied with cheap HID kits are often made of small gauge wire that is not a good fit for the high levels of power and long distances often involved when installing HID headlights. Always select kits that have high quality wiring harnesses using appropriate sizes of wire and make sure to create excellent crimps when installing.

Additional Components

Many vehicles including any make built after 2006 and about a dozen other manufacturers regardless of year will require xenon HID warning cancellers or anti-flicker capacitors. This device keeps your car’s computer from failing to recognize the presence of HID bulbs. Many vehicles won’t work with HID systems without a warning canceller.

Many vehicles that have daytime running lights can have problems with compatibility of HID headlights. The reason is that DRLs require lower voltage than when headlights are fully powered on. Due to the design of HID lights, the lower power doesn’t allow the bulbs to fully energize, causing flickering. You will need to set your vehicle to have DRL off to use these kits. If your vehicle can’t turn off DRLs, you should not install HID lights in your car.

Tricks for Getting Proper Alignment

A lot of the aftermarket kits promote their products as “plug & play” when they are not. The reason is that you can’t simply replace a halogen bulb with a xenon bulb and get consistent performance. The halogen bulb and reflector are designed to produce light within a specific beam, eliminating the tedious task of manually adjusting headlights.

When you swap in HID bulbs, the reflector no longer focuses the beam of light properly. This is almost always the reason HID headlights shine into other lanes of traffic rather than down the road. There is no easy solution to this problem unless your vehicle had HID headlights as an available option. In that case, you’ll want to source original HID headlamps even if you plan on using an aftermarket light kit.

The other solution is to cut the reflector to allow the HID projector to fit through, then add brackets and a manner of tilting the bulb horizontally and vertically like the headlights of classic cars. Success in customizing your factory headlights will depend on the type of bulb you are using, the shape of the reflector, and your ability to mount the bulb in such a fashion as to provide adjustment.

Conclusion

Installing an aftermarket HID headlight system in your car can provide you with better lighting and a safer driving experience. It’s unfortunate that many of the systems on the market are low-quality and make for a poor substitution for factory halogen headlights. There are an endless number of articles online dealing with troubleshooting low-cost HID systems which makes it clear these products aren’t worth the hassle. A high-quality HID system isn’t cheap, but if you are trying to get the kind of superior lighting you see on some of the most popular European cars, making the correct purchasing decisions is vital. You don’t want to experience your headlights suddenly going out on a dark, country road or even a well lit city street.

Solving most of the problems with poor HID light performance involves inspecting wiring and connections. You’ll often trace the problem to a bad ground, a short in a power wire, or a crimp connector that has come loose.

The most important thing to remember when troubleshooting HID systems is to start with the simplest solution. That typically means checking the grounds and power connections for faults. If you have an issue on one side of the vehicle but not the other, try switching one component at a time starting with the bulb. If the problem persists on one side, you know there is an issue with wiring. Otherwise, you’ll find the faulty component because the problem will follow the part.

Troubleshooting these systems is all about taking your time and checking one thing at a time. A good electrical diagram for your vehicle will make the task much simpler. Before you begin any work on the electrical system, have high-quality wire crimpers and proper connectors on hand to do the job correctly the first time.