2000-2002 Buick Century

Locate Body control Module (BCM). This unit is a black box approximately 6" square and 1-1/2" thick with 4 connectors entering one end. Hunting with the door open and key in the ignition, follow your ears to the chime inside. On the 2000-2002 Buick Century, it resides to the left of the steering column, right above your left foot. There is a bump in the fuzzy trim panel that covers the under dash area that gives clearance to the BCM wiring harness. The trim panel does not have to be removed completely to get in far enough to work. Pull out a couple of the panel retainers and work the left end down and back until you have working room. Those panel retaining fasteners are a push in "Christmas tree" type and can be difficult to remove. Persevere, this is the hardest part, The actual mods are easy.
The 4 connectors should now be visible almost even with the bottom of the dash. The connectors are color coded for identification. The first connector is C1, and is blue. We will be working with 4 out of the 7 wires in this connector. Locate the light blue, light blue w/white stripe, dark blue, and dark blue w/white stripe. The white striped wires are the front left and right feeds from the turn signal switch. The plain color wires go to the front left and right turn signal lamps. Very simply, cut all 4 wires about an inch from the connector and separately insulate the wires from the connector. Splice (and insulate) the like colors together that go into the harness. Dark blue to dark blue w/white, and light blue to light blue w/ white stripe. This removes the DRL function from the front turn signals.
The second connector is C2, and is purple. We will be working with only 2 of the 14 wires in this connector. Locate the yellow w/black stripe, and immediately adjacent to that, find the light green w/black stripe. These two wires connect to the Ambient Light Sensor. Cut these two wires about an inch from where they emerge from the harness. Connect a 4700 Ohm resistor (1/4 watt is fine) across the wires from the connector, and insulate. This makes the BCM stay in the daylight mode, and disables the automatic headlight function.
Test your work. Check operation of turn signals and headlights. Replace trim panel and congratulate yourself for a job well done.

Also If you have the clear corner marker lights that light solid when turn signal is on and think its a waist of power and would like to make it a turn signal & marker light like the inside turn signal for added marker and turn signal its easy to do turns out gm used same light base as the turn signal all you have to do is replace the clear bulb with a 3157 or 4157 bulb the bulb change alone gives you a marker light there and to add turn signal cut the yellow(orange) wire on corner light as far from the light base as you can then splice in a longer wire and run to the white turn signal wire on turn signal light base there you go
I have done All of the above to mine with no problems I hate auto lights and DRL'* and hated the turn signal only being the one on inside of high beams

This is the old headlight assembly I have since replaced with new ones and done same mod to them as well will update pic
Also done the 4 resistors to repair odometer and PRND21 Indicator anyone reading this and have the Indicator not working you will more than likely need all four 150 ohms 1/4 watt resistors cause three of the four on mine was already gone and #4 Disappeared when I touched it. If you can solder its a 15 to 25 min fix total from pulling the cluster to done




Also have these fixes for other Buick and Gm Vehicles