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PIAA Tera LED Sidelight Install

A guide to installing PIAA Tera LED sidelights on the MK2 Honda CRX.


After installing my HID Conversion kit, it became apparent that the standard sidelight bulbs would have to be replaced - mainly due to the startlingly obvious colour difference between the headlight and sidelight. The HID conversion is so powerful that it almost washes out a stock sidelight.

After looking at the various options, I decided to go for an LED type of sidelight. While you can get standard wedge lamps with a clear (as opposed to yellow) output, I decided not to take the risk and go  for a quality LED replacement.

There are a number of LED replacement sidelights on the market, the majority of which are constructed with industry standard 5mm led's crammed into a package with a wedge shaped base. The main problem with these is the the narrow viewing angle - even a "wide angle" LED cannot compete with a standard incandescent lamp. Many cheap LED sidelights are also run right on the limit of their specifications to try and make up for the difference in light output, which shortens their life dramatically. High output white LED's are still very much a technology in development and white LED's that can start to compete with incandescent lamps have only been on the market for a few years and are still quite expensive which tempts manufacturers to overrun them.

Because of the wide, open design of the CRX's sidelight I needed a LED with the widest viewing angle possible, hence the choice of the PIAA Tera sidelight. I couldn't find anything to match the specification of these sidelights anywhere else, and they came recommended from a number of sources. Of course if you know of better performing lamps, please get in touch!


PIAA Tera LED Sidelight

The PIAA Tera lamps use a high output 1w SMT "chip" LED, bonded to a heatsink with a lens to help distribute the light even further. While not being the cheapest on the market when you consider the construction and lifetime of them it's actually reasonable value for money. The "chip" type of LED that PIAA use is far better suited than the cheap alternatives most other LED sidelights use. PIAA products are never cheap, but their quality is way above the competition and they include everything you need for the install.


The Kit

Due to the available space and high output the current limiting resistor for these lamps is spliced into the wiring to the lamp itself.


The kit contains:

  • LED Sidelights
  • Resistors
  • Tyraps for securing wires
  • "Scotchlock" style connector kit
  • Bullet connector kit
  • Instruction manual (in Japanese)



Installing the sidelights is almost as simple as replacing a bulb, however you MUST fit the resistors first! Plugging the LED lamps in without the resistor will burn them out very quickly. PIAA recommend you install the resistor in the positive wire, and while this is best practise it doesn't really matter in most installations. As long as it is in series with the lamp, you're fine.

The installation instructions in English can be downloaded below:
  piaa-tera.pdf (122k)

Follow your car's owners manual on how to replace the sidelight lamp. If you have a VTEC style MK2 CRX, the sidelight is held in by a recessed screw at the top of the headlight - undo it and gently slide the sidelight forward being careful not to break the tab through which the screw fixes, as it is delicate.

If you have a non-VTEC style MK2 CRX, then undo the two exposed stainless steel screws and the light will simply lift out.

I would recommend you use the bullet connectors supplied with the kit - these are high quality Japanese types and complete with waterproof boots. Keep clear of using the scotchlock style "wire tapping" connectors - although the ones PIAA supply are of a good quality, this method of connecting wires should be avoided at all costs as they are prone to corrosion and loosening their grip on the wire over time. They also make the install very messy, however it is good they included them as an option for those that don't have a crimp tool or soldering iron for the bullets.

I chose to install my kit by tapping into the wires and soldering them directly to the resistor, and using heat shrink sleeving for the neatest possible install. However this does mean if you wish to revert to standard lamps it'll take a minute or to to wire it back up as standard. If you want the option of easily running standard lamps again, use the bullet connectors as shown in the installation instructions. This lets you remove the resistor and couple the wires directly if required, although remember and remove the LED lamp first!!

Now they are installed, time for a test before fitting the sidelight back on. As the PIAA lamp is a LED (Light Emitting Diode) it will only work when plugged one way round. In this case just remove the lamp and turn it round in the holder. Having the LED plugged in backwards won't damage it - it just won't work. PIAA do actually mark the positive lead of the lamp with a small dot on the back of the holder, see the instructions for details.


The Results

As you can see the Terra's are impressive - it's hard to take accurate pictures of something like this, however you get the general idea.

The slight tinge shown in the left hand picture is nothing to with the PIAA lamp, it is because the sidelight on my car is 15 years old and slightly affected by the elements! The picture actually accentuates this difference and as you can see in the right hand picture (which was taken in complete darkness) the sidelights are a pure white, with no hint of blue whatsoever. The colour temperature of the Tera's is said to be 4500k, and it certainly matches up to that in real life.

If you're feeling generous you could always buy a pair of new sidelights, which will make a large difference, but they are very expensive from Honda, approx 50 per side! You can give your old, tired sidelights a lift by using some cutting compound and then polishing them (try this first), or in severe cases lightly sanding the face with 1500 grit wet and dry paper beforehand.

Here are some better pictures, comparing the 4500k sidelight to the 6000k HID conversion. The PIAA's obviously aren't going to be a perfect match for a 6000k HID, but a heck of a lot closer than a stock lamp. Again the camera shows up a difference between the colour temperature, but it is barely perceptible when viewing them in person. You really have to try a set of them on the car in question and decide whether it is for you.



If you have a set of "white" headlight lamps or a HID conversion, then you need a set of these. As i've said, The design of the CRX sidelights isn't ideally suited to LED's so they will work better on cars that have a more shrouded design.