Project Unlimited

SVA Passed

In this section I am going to cover the alteration that are necessary to get an American imported JK Wrangler through the SVA test. The main item that needs to be altered is the lighting, the US spec is as follows:-

  • Side/Park Lights are Yellow. (See photo 1)
  • Side Markers are flush, and do not act as side repeaters. (See photo 1)
  • Head lights do not have Side/Park Lights. (See photo 1)
  • No rear fog lights.
  • Red indicators on rear combined with brake lights. (See photo 2)

US Spec front lighting

US Rear light unit

For the SVA test I have already altered the front lighting, as follows:-

  • Fitted UK spec side repeaters, and altered wiring so they now flash with indicators.
  • Fitted E Marked head lights with side/park lights and altered wiring.
  • Disconnected the yellow side/park lights, so now act as indicators only.

Front lighting UK spec.

As you can see from the photo above the side repeater now protrudes from the flares, and you can see the side/park light in the head light. (It would be possible to alter the original headlight unit to fit a side/park light, but after talking to some guys in the States they recommend changing the lights as the light pattern was not very good, a lot of them are changing over to E Marked light as they prefer the light output). The lower side/park-indicator now only acts as an indicator.

At present I am still working on the rear lights as I intend keeping the US spec lights as I prefer the look of them, with the built in reflectors. I will make the reversing lights the indicators, as with other Wranglers they are not that good for reversing. The main problem is the rear lights are computer controlled, so it is more complicated then just changing wires around. I am hoping that the computer can be programmed to the UK code for lighting, if that is the case then it will be a matter of running a couple of extra wirers from under the dash to the rear and changing a couple of pins around on the rear light connections.

For the fog lights I will be installing them into the rear bumper and running a separate harness, with a switch on the dash.

UPDATE 13th March 2008

For the rear lighting I have done the following

  • Changed the reverse lights to indicators
  • Stop brake lights flashing when indicators are operated
  • Fit fog lights

After further investigation I have found that the rear lights cannot be converted by changing the computer country codes, so it is a matter of altering wiring, and fooling the computer. The basics are that the feed to the rear brake lights/indicators have to be connected to resistors so the computer does not realise that there are no bulbs connected, otherwise it shows up as a blown bulb. Then a signal wire has to be taken from both front indicators to trigger fast acting relays to operate the rear indicators, so as not to over load the front indicator circuits. The brake lights have been tapped into the high level brake light circuit.

Resistor Pack

Resistor pack with heat sink, the reason for the heat sink is that the resistors will get hot as they will have power running through them when the brakes are applied as well as the indicators are on. This is the reason for the heat sink, I have mounted it under the bonnet for good air flow.

I have now also fitted the rear fog lights, this would seem like a fairly simple wiring as they have to work with low beam only, and this would normally only involve tapping in to the feed to the low beam light circuit. But; the feed to the low beam headlight in not straight 12 volt dc, but a modulated 12 volt with the return back to the computer. So if a feed was taken to another bulb, then to ground, this would throw up an error on the computer.

So a relay has to be triggered using the feed from the low beam circuit, and the ground for the relay has to be taken back to the headlight circuit. Again the relay would oscillate as the modulated feed to the headlight would not hold the relay open, so I had to build a control box. I built it with a high beam relay as well for later use. Now with a clean low beam feed it was a matter of wiring up a switch with warning light, and running the feed back to the fog lights I mounted in the rear bumper.

High/Low Beam Relay Box
Rear fog lights fitted.

With the rear fog lights fitted the rear is now finished, I could have fitted a single fog light, but I personally prefer two. These particular lights only protrude 15mm from bumper.


The SVA test is now confirmed for Monday 17th March, so as long as I have not missed anything, I should be able to start on the rest of the project.



Last Updated 13th April 2008,
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No Side/Park Light Flush fitting side marker Side/Park - Indicator