1. Empty your glove compartment and release the spring clip on the left. This will permit your glove compartment to fall outward. Reach into the left portion of the opening and try to find an unused single row 12 pin connector. It will be somewhere between the radio and the glove box. This cable is for the TS amplifier/controller.
   
   
2. Next, remove the large bezel which covers the instrument panel. Right above your left leg is the headlight switch bracket and just to the right of the instrument panel dimmer wheel is an empty socket. Peek in and make sure there’s an electrical connector for another "dimmer" control. When replacing the IP bezel, note the appliqué plate where you will have to cut out a hole for the new TS delay control wheel.
   
   
3. To locate the photocell connector, remove the radio panel outer bezel and then remove the air conditioning control panel (4 screws). This will require disconnecting several connectors and vacuum blocks. Reach into this hole and try to find the unused 2 pin connector to the left. Mine had black and white wires. You are now ready to order the parts.
   

• Photocell 16502712
• Delay Control "Switch" (resembles dimmer wheel) 01987384
• Amplifier/Controller 00914027

By some other means, you may want to acquire the following, but they aren’t entirely necessary:

• A dash top with a grille cutout for the photocell
• An instrument panel bezel with proper appliqué for Twilight Sentinel
• The proper bracket for securing the sentinel amplifier module inside the dash
  

As an alternate to the above three, I used:

• Rubber grommet (see text) & epoxy
• Exacto knife
• Wire tie
  

Follow step 2 to access the socket for the delay control. This time you will remove the headlight switch bracket assay (3 screws) and snap the delay control wheel into the bracket with the other switches. Be careful to observe the orientation of the mating socket it will go into. Mine was oriented opposite of the instrument dimmer such that the little white dot clicks at the bottom of travel instead of the top. Reinstall the bracket assay, but leave the IP bezel off until you have tested the system.

Note: If you do not have a new instrument panel bezel with the Twilight Sentinel appliqué, you will need to cut out your existing appliqué hole with an Exacto knife. The IP bezel will not clear the delay control wheel without that hole cut out.

MOUNTING THE PHOTOCELL

1. You will need to mount the photocell on the top dash panel (the one with the speaker holes). If you have located a proper GM grille assembly, great. I chose the method below, but you can use your own imagination.
   
   
2. Drill a "peep hole" in the top dash panel (about _") to allow light to the photocell, which will sit flush on the underside of the panel. The photocell wire is rather short, so I chose to drill the hole left of center, where the connector will come from, but clearing any obstruction below by at least 1 inch.
   
   I scuffed the underside of the top dash panel around the peep hole and epoxied a soft rubber grommet to the underside, centered around the hole. The grommet I used (similar to Radio Shack #64-3025, but larger to accommodate the photocell) is designed to protect wiring going through sheet metal holes. In this application it does not go through the peep hole though; it’s simply glued underneath to hold the photocell. A piece of industrial sponge or foam with a hole burrowed out may substituted for the rubber grommet.
   
   
3. Make sure the photocell can seat dead center and FLUSH with the underside of your peep hole, so it can see low-angle light. Do not glue the photocell itself, since you want it to be replaceable. You may wish to trim the photocell’s "ears" to assure a nice snug fit.
   
   
4. Before you secure the photocell, follow step 3 above to access the connector behind the A/C controls. Fish the photocell wire down from the top until you get them mated behind the dash (easier said than done). Gently push the photocell into the grommet and seat the dash top normally. Don’t screw it down until you test the system.
   

1. The delay control wheel turns the system on and controls the headlight delay after you shut the ignition off. The TS system is off when the delay control wheel is parked at the "click". When you turn the control on, the wheel varies the delay between 5 seconds and 4 minutes after ignition is keyed down. If it’s dark when you first start the car, the system will come on immediately. Otherwise, it takes about 30 seconds to react to changes in photocell light. This is called hysteresis and prevents it from falsing in shadows.
   
   
2. To test your system, first turn Twilight Sentinel off and start the car; make sure regular headlight operation is normal. If OK, turn the car and headlights off.
   
   Cover the photocell and turn the TS on to the shortest delay. Turn the key to ignition, and the lights should come on immediately. After a few seconds, turn the car off. The lights should stay on for several seconds and turn themselves off. The delay control wheel adjusts this "hang time".
   
   
3. With the Twilight Sentinel still on, shine a bright flashlight at the photocell and start the car- the headlights should remain off. Remove the flashlight and cover the photocell again. The lights should come on within 30 seconds. You may hear the relay clank behind the glove compartment Shine the flashlight at the photocell, and the lights should turn off within 30 seconds. This reaction time is not adjustable.
   

Now that you’ve exercised the system, button up all the open panels and try it in the real world for a few days. If you encounter trouble, you will need to consult the Buick Manual for the complete testing procedure. When troubleshooting, I would suggest reseating all the connections first. Also, many problems relate to improper lighting/shadowing of the photocell