Dome Light Dimmer Circuit for 91-93 Caprice
Parts List: R1 = 27K R2 = 27K C1 = 100µF, 25V D1 = 1N4148 or any diode would work i.e. 1n4004 Q1,Q2 = 2N2222 or equiv. Q3 = TIP31 or equiv. Heatsink for Q3
1 ft. black 18ga.
1 ft. green 18 ga.
The positive (+) green wire goes to 12V side which is switched by the door switch. The other wire (-) black just goes to a ground or chassis.
Used a Drimmel to carve out the traces on the circuit board following the layout I did on the computer then soldered in all the components. Circuit is simple enough you could even breadboard it.
Mounted it in a cheap plastic box from Radio Shack
Finished it with a label
Removed the undercover on the right side of my wagon and took loose the foot well lamp assembly. Connected the green wire from the box to the white wire of the lamp. Connected the black wire from the box to a ground screw under the dash by the side cover. Tie wrap the box in place behind the kick panel so not to rattle. Done and works like a charm...