I did this the other night, YES NIGHT!
Bought footwell lights and never really used them, only for finding crap out of my girlfriends handbag on the passenger floor, it goes negitive constant positive then negitive (Dependent upon doors), I also wanted the option to have the footwell lights on with the door shut, so I bought from maplin for £3ish a break before make switch, I wired the two negitives to the switch then the positive went straight to the lights so effectivly
Door dependent negitive Positive Negitive
| |
---------BREAK BEFORE MAKE SWITCH--------------
This way I can choose whether it works on the doors or whether to override and have them on,
Another bit of useful information is if you leave them on all the time they turn off with the central locking.
Took me about 1 hour most, You could solider on the end of the of the light (the three points but risk melting the plastic, drill holes in the light and solider the inside or finally choc block the 3 wires before the light)
Good luck peoples!