How to: Add overhead 'ambient' LED lighting

[blindman10]

How to: Add an overhead ‘ambient’ LEDWARNING: Picture heavy thread!!!This thread details my process of adding a single ambient/accent LED to the maplight/sunroof fixture in a 2003-2008 Vibe, if you have a different year/model you may need to modify the procedure.This write describes how to wire the LED into the existing illumination in your car so that it is controlled just like your dash illumination, which only comes on when your headlights are turned on my the ambient light sensor (or manually on the steering wheel). The dimmer also controls the output of the LED.I’m unsure if any modifications to the DRL, foglights or the light sensor will affect this project. If you are concerned, or do do not want it wired into your illumination, you could also simply install a switch to turn the LED on (wired to a constant 12v) or straight to a wire so that it is always on when your car is running.Before I start, I’ll get this out of the way…DISCLAIMER: Do this at your own risk, don’t electrocute yourself, don’t be stupid…if you are, it isn’t my fault. I am not responsible for any harm or damage to cause to yourself or your car. There, done.TechnicalFirst the technical stuff. If you DON’T want to modify the procedures and are going to use the EXACT same components then this part can be skipped. If you intend to use a different type/color/size LED then I advise reading this.I first probed the wire harness I intended to use to ensure it would work. I’m using the illumination wire on the rear defroster harness.I probed the green wire on this harness and grounded at the radio.Here is the reading with the car running but the headlights off.Here is the reading with the car off and headlights on.And now the car running with the headlights on.To be safe, we will assume 14 volts.Now, determine the LED you are going to use. I am using a 5mm red LED that produces 8000 mcd in a 30 degree viewing angle. It has a forward voltage 2.2 volts and current of 20 mA (0.020 amps).To determine the minimum resistor value, use this formula:Resistance = (Vsupply-Vled)/CurrentIn my case:R=(14-2.2)/0.020R=590 ohmsThe nearest common resistor value is 680 ohms.Now we need to determine the wattage of the resistor used to ensure it can disperse the heat as it steps down the voltage to the proper level for the LED. Using the following formula:P=I*VP=0.02 amps * 14 volts = 0.28 wattsTo be safe, this amount should be doubled, so 0.56 watts. In this case, its safe to round down a tiny bit and use a 680 ohm resistor rated at 0.5 watts. That wasn’t so hard, was it?

[blindman10]

Tools:*dremel (with a cutting wheel)*drill/drill press (I used 1/16, 11/64 and 3/16 bits – but you can get by with only 3/16 for a 5mm LED)*screwdrivers (various sizes of flat and phillips)*wire cutter/stripper*voltmeter (optional)*hot glue gun (optional)Supplies:*LED of your choice (5mm red LED #RL5-R8030 SBL.com)*wire (approx 9 ft of 18 gauge wire, #WP18-2 SBL.com)*resistor(s) (depends on your LED, I used a 680 ohm ½ watt carbon film #271-1117 RS)*wire connector/plug (male/female 2 prong #274-222 RS)*wire splicer (item #WST-184 SBL.com)*shrink wrap (6 inches of 1/8 inch wrap #DWS-125 SBL.com)*ring connector (large enough to fit ground screw)*electrical tape*soldering iron/solder*hot glue (optional)Optional:*2nd maplight/sunroof overhead console fixture (only necessary if you want to return your car to stock OR are afraid you will mess up – got mine on eBay)SBL.com - http://www.superbrightleds.comRS - http://RadioShack.comAll things considered – this project cost me about $40...and I have a lot of left over stuff (resistors, wire, extra LEDs, etc). If you purchase exactly what is needed from the same places I did, you will spend just under $30…or under $10 total(before shipping) in supplies if you don’t order a 2nd console fixture.Modifying Maplight/sunroof fixture*remove the fixture from your headliner (unscrew the outer screw, pull the cover off, unscrew the 2nd screw, slide the unit to the right and then pull down to the left to separate from the headliner. Unplug to connector)*using a flathead screwdriver or two, carefully remove this little black box. It is held in by four little ‘clips’*with the black box free, remove the two screws on the back*using a screwdriver, remove the top of the black box. Be careful, the circuit board is inside so don’t be too aggressive with poking the screwdriver around. There are four ‘clips’ on this as well (picture shows two of them). I found it easier to remove the side opposite the wires 1st.*once the top is free remove it and set it aside. It may be ziptied to the wire harness, but I was able to wiggle mine free. If not, cut it off.*take the board out of the black box. Under the board there should be 4 little white ‘buttons’ that sit inside the sunroof controls. They will come loose. Just dump them out and put them someplace safe.*use a small flat screwdriver to pry the two sunroof buttons off. If you pry the inside hinge first, they come right off.*set everything else aside besides the empty black box*carefully measure (twice) to determine your drilling location. I used a sharp knife to slit the plastic surface to mark it. A silver sharpie would probably work to. I measure 3mm from the edge of the ‘hole’ and then down the center of the side to make a cross.*using your smallest drill bit, carefully put it in the exact center of your cross and tap it to indent the plastic.*now drill away. Make sure you don’t drill into your wife’s kitchen table. As you can see, I used an old college textbook I used progressively larger drill bits to make sure I didn’t go too large.You want the hole to be *just* big enough to fit the head of the let thru.*now grab the fixture housing again and snap the black box (still empty) back into it *snap the cover onto the fixture*using your previously drilled hole as a guide, drill a hole in the exterior plate just as before EXCEPT I went a tiny bit smaller. The LED won’t actually stick out of this hole, it is just for the light to pass thru. If done correctly, the LED will be recessed and less obvious. BE CAREFUL with this hole as it’s the only part of this project that anyone will see!*once that is done you need to make a hole for the wires to exit*I used my dremel with a cutting wheel to grind an area out, just large enough for the wires to exit without piching or rubbing. Test fit your wire. Note: This is cut thru the side opposite of where the LED hole was drilled.Wiring the LED*now take your LED and solder a length of wire to it (red to +, black to -). I used enough to have about 4-6 inches outside of the black box. If you are using heat shrink make sure you put it over the wire BEFORE soldering.Note: Keep in mind that the LED and wire will be a tight fit and will have to fit around the large black part of the circuit board.*cut your positive wire about 3 inches away from the end and strip the end (keep the piece you cut off)*solder your resistor(s) to this lead*now take the part you just cut off, strip the end, and solder it to the other end of the resistor(s)* cut the positive wire to match the length of the ground*cover your resistor(s) with electrical tape or heat shrink*attach your wires to the connector/plug*ensure that you have no exposed wire/leads before continuingClosing the Maplight/sunroof fixture*snap the two sunroof switches back on and install the little white ‘buttons’*put the led in. Depending on your drilling job and size/length of your led, you may have to do some fitting/adjusting of the LED to ensure it is straight and won’t move around. I used a 9 volt battery to light the LED and did some tests holding it up by the roof. Use hot glue tosecure the LED if needed. I ended up just using a few pieces of electrical tape.*Put it all back together! Run your wires through the hole, install the circuit board, snap the cover on, screw in the two screws, snap the black box back into the larger part. Done!Installing the Wires (inside the car)*disconnect the neg battery wire and position it to ensure it won’t recontact the post. This is IMPORTANT!*using a screw driver (or just your fingers) pry the a-pillar trim loose from the car. It is held in by two clips and then slotted into the dash. Pull it straight toward the passenger side until the two clips pop off, then pull it straight toward u (hinging at the bottom) until it snaps free of the dash. Just be careful not to break or deform this piece*remove the two screws holding the driver’s side sun visor on*now grip the sun visor clip and twist it 90 degrees and remove it.*carefully pry the radio trim panel up from the bottom, swinging it toward the roof to release it from the top ‘hinges’*take a length of wire approx 8 ft long and attach the other end of your connector/plug. Make sure the polarity matches.*now take this wire and start by feeding the other end thru the hole in the headliner where the maplight fixture belongs. This may be difficult, but carefully feed the wire directly to the front of the car, having it exit near the rearview mirror. If you area having a difficult time, it may be easier to remove the passenger sun visor and pillar trim to drop the entire front of the headliner.*now pull the wire thru until you have a few inches and your plug sticking out the hole*carefully pull the front edge of the headliner down as you run the wire toward the a-pillar, stuffing the wire underneath it as you go*feed the free end of the wire thru the gap at the bottom of the a-pillar that exits underneath the dash.*now the fun part, get down on the floor and carefully feed the wire from the a-pillar to the opening behind the radio bezel. When doing this, try not to route the wire around other harnesses or the steering linkage. I found it easier to run the wire near the black tubing for the dash air vents.*on the back of the defrost button unit locate the green wire (illumination). This was the top right hole when looking at the harnesss.*using a wire splice attach the positive end of your new wire to this green illumination wire*crimp a ring connector onto the ground (black) wire and attach it to your ground of choice. I used the radio since we are right in the area*ensure there are no exposed wires and ensure your new wire is secure*plug the defroster harness back in and reinstall the radio trim*before closing everything up, grab your newly modified maplight fixture and plug it into the connector*reconnect the negative wire to the battery and test your wiring. Ensure that the LED lights when it should. If it works as desired, put your car back together.*reinstall the visor parts, a-pillar trim, radio trim, and maplight fixtureFinished!Here is the spread of the light at various shutter speeds. I’d say somewhere in the middle looks more realistic. It is bright enough to read a map if needed. The spill seems to be the brightest from the shifter to about halfway across the center console storage compartment and stops about 6” into each seat.Good luck! Post your results and ask questions if you have em...it took me a while to get everything together so I may have missed something!

[jkm311]

One of the best write-ups I've seen to date. Well done, Zach.

[Water boy]

And just how much beer will it take for you to take this mod on the road. You know, like a bunch of us will meet at a local liquor store's parking lot and you mod away while we supervise?

[blindman10]

Better make sure I don't partake in the 'payment' until its finished!Honestly it would be relatively easy. I would even venture to offer to do the drilling and installing of the LED if you will pay shipping. Unfortunately you would still have to run the wire from the ground/illumination yourself.

[blindman10]

I just wanted to add, after having this mod for a few weeks, I noticed that the brightness of the LED tends to bleed through the light colored plastic a little bit. I simply colored the back of the plate near the LED with a black sharpie...problem solved!

[Water boy]

Figures... I have the lights in the bottom of the inside rear view mirror.

[A Psycho Martyr]

to tha top!