Courtesy Lighting Upgrades
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Courtesy Lighting Project

Weary of living with a continual reminder of the austerity program that had been applied to the Cobra every time I reached for something in the glove box or console at night, I decided in 2013 to address the absence of courtesy lighting in those locations. While I was at it, I figured I'd add some lighting to other locations that were either unlit or poorly illuminated. These included the engine bay, the foot wells, and the trunk. I ruled out the usual parts store junk, nor was I interested in the tacky LED strip lighting that is popular nowadays with the ADD "Video Game Generation." I wanted real, OEM quality automotive lighting.

After some preliminary measurements, I had a reasonable enough grasp of the size and placement limitations the Cobra presented to embark on a search for suitable lighting solutions. Eventually, I found exactly what I had in mind. I ordered up a fistful of Audi/VW lamps for the interior and trunk. My choice for engine bay lighting was a Chrysler-Dodge underhood lamp assembly with an internal tilt switch.

All of the lamps are equipped with diamond pattern lenses to provide good light dispersion over a broad area. The Audi / VW lamps contain Sylvania #2825 xenon bulbs that produce 50 lumens of light, which is ample for their designated duties. The underhood lamp is equipped with a Sylvania #562LL bulb rated at 75 lumens - plenty bright enough for its intended use.

I wanted all the lamps to operate just as if they had been factory installed, which meant feeding the foot well lamps from the GEM’s "courtesy lighting" circuit and connecting the glove box, the console storage bin, and the new trunk lamps into the GEM’s "battery-minder" circuitry. Due to its nature, this project demanded a considerable investment of time. In addition to my parts search and a preliminary design effort, which ate up a number of days, the actual installation required more than 40 hours of dedicated effort. However, the installation time did include substantial field engineering that became necessary to circumvent several unforeseen obstacles.

Glove Box Lamp

The first item on my project agenda was the installation of a lamp for the glove box. The glove box hinge assembly is secured to the dash panel by a couple hex screws (rightmost screw partially removed and circled in red in the photo below).

 

The easiest way to remove the glove box is to leave its door latched shut, remove these screws, and then open the door and remove the entire assembly. Once the door is open, it’s best to tilt the box slightly down on the right, guide its right retention tab through a slot in the opening, and pull the right side out a little ahead of the left. The entire assembly will slip right out.

I decided on a simple pin switch to energize the glove box lamp, so I drilled a hole in a suitable spot behind the base of the door and installed the switch there. The dash frame is metal and provides a good chassis ground for the switch. I had a rubber cap left over from a previous project that was a perfect fit for the pin, so I added it as a bumper, but this wasn’t strictly necessary. I then connected a suitable length black ground wire to the back of the pin. (Refer to the photo below.)

 

In this location, the switch is completely concealed with the door installed, yet functions perfectly to energize/de-energize the lamp when the glove box is opened and closed.

Next, I cut a hole in the glove box back panel where I had decided to mount the lamp.

 

After installing the lamp in the cutout and confirming the operation of the pin switch with a continuity tester, I was ready to wire the assembly into the GEM’s “battery minder” demand lighting circuit.

 

Here’s a shot of the finished glove compartment lamp in operation. This photo was taken from a low angle to show the lamp, but the illumination it provides is all that is visible during most normal use.

 

For power, I tapped into the GEM's demand lighting circuit near the 3-pin connector at the base of the passenger side A-pillar. To prevent draining the battery due to a stuck or shorted switch, the GEM monitors this circuit, and will deactivate it after several minutes if the ignition is off. The same 3-wire harness also contains a hot wire for the courtesy lighting circuit, so I sourced the power for the foot well lighting from this harness, as well.

Console Storage Bin Lighting

Next up was lighting for the console storage bin. The bin is secured with a number of spring-type retainers and two hex screws that are concealed beneath a removable fabric lining in its bottom. After the screws have been removed, the bin can be popped out with a trim fastener removal tool.

Using the same style pin switch that I had installed for the glove box wasn’t an option. There isn’t enough clearance between the top of the console and the underside of its lid for one of those, so I opted for a miniature normally-closed momentary SP pushbutton switch, which was perfect for this spot. (See below.)

 

I cut a lamp hole directly over the storage bin’s power port. The photo below shows a test fitting of the lamp, however, because of the power port, the bin must be inserted in the console at an extreme angle that precludes having the lamp already in place when replacing the bin. This meant trimming the hood on this particular connector, so it could be pulled through the cutout for attachment to the lamp. This enabled the entire assembly, with its connector attached to be snapped into the cutout after the bin was in place.

 

Here’s a view of the lighting fixture from the outside face of the storage bin ...

 

This is what the reinstalled bin looks like with the new lamp in place ...

 

... and a shot of the storage bin lamp in operation after reconnecting the battery.

 

The storage bin lamp obtains its power from the same GEM “battery minder” demand circuit as the glove box lamp. One of the pushbutton's terminals is connected to chassis ground, and the other is connected to the negative pin of the lamp assembly. Grounding to complete the lamp's electrical circuit is provided by the pushbutton when the console cover is open and interrupted when it is closed.

Foot Well Lighting

Third on my project list was courtesy lighting for the foot wells. I found sufficient room to accommodate the lamps behind the kick panels, which was a great spot from which to illuminate the front floor. This is the passenger side panel after I had installed its lamp.

 

If you're curious - or not, the cutout at the top of the panel is where a DB-9 serial port is normally located. I can perform fuel trim programming via my MAFterburner unit by connecting my laptop to that port. MAFterburner details are located on this site's Electrical/Electronics page.

Below are a couple shots of the driver side kick panel after I finished adding its lamp, one from the cabin side and the other from the back.

 

 

The round hole at the top of this panel, forward of the hood release cutout is where the valet button for my dealer-installed Ford “System 3” security module is normally located.

Here are a couple photos of the new courtesy lighting in operation after installation of the modified panels and connection of their lamps …

 

 

Power for both of these lights was sourced from the courtesy lamp wire beneath the passenger side A-pillar, and the lead for the driver side was run through the dash to that lamp. Each lamp's negative lead was connected directly to a chassis ground lug.

Engine Bay Lighting

Third up on the agenda for this project was lighting for the engine bay. I mounted the underhood lamp assembly to a Z bracket that I had fabricated for it, and then secured the bracket with the rear screw of the driver side hood hinge. I picked this location because everything I am likely to be interested in accessing by the roadside after dark is located on this side of the engine bay: battery terminals, battery junction box, dipstick, and fluid fill locations.

 

In the above photo, the lamp’s connector has been snapped on for clearance testing. I would have preferred to mount the assembly with the connector facing back toward the firewall, but the lamp's internal tilt switch was designed to operate in this orientation.

The shot below, taken from the passenger side, shows the primary reason for my concern regarding clearance. The inline fuse holder for the power lead to my subwoofer’s amp is mounted to the side of the engine bay just below the lamp. Clearance with the hood closed is minimal, but there’s no contact.

 

This is an ideal spot for the lamp. It’s reasonably distant from hot engine and supercharger surfaces, and it enables good lighting of the underhood area I want illuminated. Below is a photo of the lamp in operation after tying it into the GEM’s “battery minder” circuit.

 

To power this lamp, I tapped into the appropriate wire coming off connector C292 at the GEM, behind the cabin kick panel near the driver side fender grommet. Since the lamp assembly is equipped with its own internal switch, I routed its negative wire directly to a chassis ground lug located on the inner fender.

Trunk Lighting

Additional lighting for the trunk was the final piece of this project puzzle. Although Taz was equipped from the factory with a trunk lamp, the OEM lamp is poorly located. It's near the bottom of the trunk lid, placing it above one's head when the lid is raised. As soon as I bent over the trunk opening, I found myself between the light and the trunk cavity, casting a shadow over everything inside there. And after I added the trunk lid toolbox, the situation became even worse, because the toolbox now blocks most of the light shining down toward the trunk, even without me in the way. I decided to install some lamps back there that would illuminate the trunk, regardless of whether or not I was leaning over its opening.

New Edge Mustang convertibles don’t have folding rear seats. Instead, their trunks are fitted with forward bulkhead panels to separate the boot from the trunk area. I elected to locate the new trunk lamps on this bulkhead. The photo below shows the panel after adding the cutouts for the lamps.

 

To avoid interference issues with the structural member to which the panel is attached at its top, I angled the cutouts to follow the arc of the frame. I then installed the lamps in the panel to confirm fitment.

 

The wires for the factory decklid lamp are among those running into the brown OEM connector at the center of the photo below. This was the most convenient spot at which to tie the new lamps into the circuit. Power originates at the GEM’s “battery minder” output, and the trunk latch switch provides grounding to complete the circuit through the lamp whenever the trunk is opened.

 

After terminating the new lamp harnesses with plugs, I installed the panel and connected the lamps.

 

Finally, here’s a low-angle shot of the lamps in operation. As you can see, they shine directly down into the storage area from above. This provides excellent illumination of the trunk’s contents.

Donut Holes

By the end the project, I had six rectangular "donut hole" souvenirs. I don't know what I'm going to do with them, but I can't bring myself to throw them out.

Circuit Details

For those interested in the technical details of the new lighting circuits, I have provided a diagram HERE. Ford changed the connector ID numbers for the Terminator Cobras. If you own an '03 or '04 Cobra and you decide to undertake a project like this, you may need to do a little digging in your service manual for the corresponding ID's. However, I believe the physical appearances and locations of the connectors noted in this diagram, as well as the pin assignments and wire color codes remained the same.

 

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