Date Registered: 10-2006
Location: Mona Vale, Sydney, AUSTRALIA
TOTAL POSTS: 6003
Mod for Map Lamp Illumination by Door Opening
Just finished a mod to make the front map lamp come on in tandem with the main centre cabin lamp when the doors are opened.
I did this because I have always thought the front of the cabin was too dark with only the main centre cabin lamp and because of the sunroof the front lamp is only an on/off map reading lamp.
The basic idea was to pickup the switch wire from the doors at the centre cabin lamp unit and run a wire to the front map lamp, through the roof space around the sunroof. To stop the front map lamp turning on the centre cabin lamp in reverse, a diode would be connected into the wiring so that current would only flow in a single desired direction.
Directions for a Series 1 with sunroof.
If anything is different in your setup from the following, contact me and we should be able to find an answer which can be added to this as an exception note.
1. Start by removing the front map light & sunroof control unit. This is done by just pulling out from the roof headboard.
2. Check with a voltmeter the voltage between the back metal panel over the globe and the chassis (metal roof panel). It should be 12V when the map lamp switch is turned on.
3. Unplug the two connectors by pushing on the locking tabs and pulling apart.
4. Examine the wires from the white connector.
The black is the 12V and the grey is ground.
These need to be reversed. The easiest way I found to do this was to unsolder the black wire from the switch and unsolder the grey wire from the globe terminal, then resolder in reverse (black to globe terminal and grey to switch).
The switch now switches the ground circuit for the map lamp which makes it compatible with the door switch circuit that is also ground switching.
5. Now for the door circuit wire connection to the map lamp.
A diode is required to stop the map lamp switch making a ground circuit back to the cabin centre lamp when the map lamp is turned on for map reading.
Crimp a suitable ring lug onto the + end (opposite end to the band) of a 1 Amp 12V diode (1N4004 available from any electronics shop for about 10cents) and solder or crimp the extension wire to the other (- end with the band).
A piece of heatshrink tubing over the solder connection protects it from touching anything.
6. Cutoff a short length of the extension wire and crimp a spade lug to the free end. Pass the wire under the strain-relief tab holding the wiring loom for the sunroof controls to stop any flexing from breaking the wire or ring lug away from the diode.
The front map lamp unit is now ready to be refitted once the cabin centre lamp unit connection has been done.
7. Transferring to the cabin centre lamp unit, remove the plastic lamp cover using a screwdriver to lever it off near the switch and locate the two fixing screws.
Undo these screws and remove the unit.
Unplug the connector by pushing on the locking tab and pulling apart (carefull this locking tab can bite and got me 8( ).
8. Examine the cabin lamp unit.
From the conector, one metal tab is the +12V to the lamp and the other is the ground from the door switching circuit. Two other metal tabs are from the lamp and the chassis ground connection.
9. Remove the switch lever screw and remove the switch lever, being carefull not to loose the small ball-bearing underneath.
The switch works by moving the ball-bearing from its OFF-position to either shorting the door ground circuit tab (left) and the lamp tab (middle) for DOOR operation or shorting the lamp tab (middle) to the chassis ground tab (right) for ON.
10. Now it is time to make a choice on how you want this mod to work.
(a) Connecting the wire from the map lamp to the tab for the door ground circuit will not allow you to turn off the door function of the map lamp. The map lamp will ALWAYS turn on when ever a door is opened.
(b) Connecting the wire from the map lamp to the middle tab from the lamp will allow you to select OFF, DOOR or ON so that the map lamp will effectively be slaved from the cabin lamp. This was my choice.
11. Turn the cabin lamp unit over and locate the retaining lug for the globe spring-clip.
Remove the globe and while pushing this retaining lug with a small screwdriver, remove the spring-clip, carefully levering it over the two plastic retaining posts.
12. Drill a hole for a 3mm screw in the plastic housing where the spring-clip will be refitted.
13. Drill a hole for a 3mm screw in the spring-clip opposite the existing hole which holds the globe.
14. Again take a short piece of wire and crimp a ring lug to one end and a spade lug to the other end.
15. Using an approximately 8mm long (thread length) x 3mm screw with nut (which should fit snuggly into the square plastic hole), refit the spring-clip to the plastic moulding and fix the ring lug to the spring-clip with the 3mm screw and nut.
Refit the globe and switch to the cabin centre lamp unit, making sure not to forget the ball-bearing under the switch and the cabin centre lamp unit is now ready to be refitted.
16. Last thing is to install the extension wire around the sunroof.
You will need about 2m of wire with the mating spade crimp connectors for the lamp units.
Remove the ceiling trim and start by reconnecting the front map light & sunroof control unit to its connectors.
Connect one end of the extension wire to the new spade connector and feed the other end of the extension wire through the ceiling opening.
Make sure you do this around the passenger's side since there is an access area for the wiring loom to the cabin centre lamp unit on that side for the wire to pass through.
17. Continue to feed the wire around the sunroof ontop of the ceiling lining, finishing by passing the wire through the hole for the cabin centre lamp unit where the wiring loom is located.
18. Connect the cabin centre lamp unit to its connector and the extension wire to the new spade connector.
19. Test the mod by switching the cabin centre lamp switch to DOOR and if a door is open the map lamp should remain on until all doors are closed and then lamp should fade off.
Remember ... there is a longer off delay if the driver's door was open.
Switching the switch to OFF should not allow the map lamp to illuminate by opening the doors, but still illuminate by its own switch.
Test the operation of the doide by switching the map lamp on and making sure it does not illuminate the cabin centre lamp.
20. After a successful test, refit the front map lamp & sunroof control unit by pressing back into place. Refit the cabin centre lamp unit with the two fixing screws and replacing the clear lamp cover by snapping into place. Last is to replace the ceiling trim around the sunroof.
Here is a video of the mod working.
The closest lamp (to the right) is the cabin centre lamp, the lamp furthest away is the map lamp.
Map Lamp with Door Function Mod
Kev X450(c) T30 Guru
03 Titanium Ti T30 Series 1 **MODIFIED**
My CarPC Worklog
25/Oct/2006, 2:33 am