I have a service truck which I use 24/7 for on call work. the issue is my flood lights are mounted to the truck and my shadow makes things difficult at times. so I used a 12v flood light and made a mobile work light.

Step 1: Assembly

you will need the following things:
12v flood light (I'd use LED but my boss is cheap)

used no good car disc brake rotor (free at most auto repair shops if you ask)

2 wire extension cord (length is up to you)

nut and bolt

electrical tape

wire strippers

razor blade (optional makes things easier)

Step 2: Assembly

cut the female end of the extension cord off at about 1-2' long.

use the razor blade to strip the cords orange(or what ever color ext cord you have) insulation off about 2-3" from the cut end
strip the two wires (black and white)

attach the white wire (ground wire) to a ground or existing bolt on the frame

then attach the black wire (hot lead wire) to you switched power source. in my case a light that was already mounted

then bolt your 12v light to the disc brake rotor in one of the holes used for the studs

next hook the hot lead wire (black wire) to the hot lead wire in the light

now hook up the ground wire (white wire) to either the lights ground wire or if the light is grounded via the mounting hardware use the not and bolt to bolt the ground to the rotor

tape up all of the connections you've made to prevent shorting

wrap the cord around the lights mounting bracket and zip tie it so it won't pull the wires from each other

Step 3: Test Light

now that its built plug it in and test to make sure it works. if it doesn't check your connections and grounds then check the switches fuse (I hope you put it on a switched fuse! ;) )

if you did things correctly you should have a mobile work light with a solid base. I plan to bolt up a bike hanger hook on my truck for easy storage of the light when its not in use.

good luck and thanks for looking and remember.....always experiment!