Using your Transformer and light kit
 

Your phone uses 4-conductor cords for hook up. The phone operation itself uses the red and green wires of the cord and the power for the light uses the yellow and black wires. For this reason, make sure the cord you have for your phone to wall connection is a 4-conductor and not a 2-conductor. You can determine this by looking at the clear plastic modular plug. You need to see four gold colored contacts and all four wires.

To use your kit, plug the T-adapter into the wall phone socket. This is a specially modified T-adapter, so don’t use just any T-adapter you might have.
Next, plug the transformer into a nearby wall outlet and plug the cord into one side of the T-adapter.
Run the line cord from the phone to the other socket in the T-adapter.

If the phone fails to light up try one of these fixes:
  1. Make sure you are using 4-conductor cords
  2. Take the bulb out and using a razor blade or sharp knife, scrape the metal contacts to shine them up. Bend them away from the glass slightly also. Use an emery board to clean the contacts of the bulb socket and the bottoms of the two metal tabs on the socket.
  3. Have the bulb checked to make sure it’s good
  4. Make sure the wiring is correct

The light on the phone is very dim to begin with. Turn the lights out in the room to make sure it’s working. You will also find on the back of your phone a switch. In one position the light will come on only when the handset is picked up. In the other position the dial will be dimly lit when the handset is on the phone, and then brighten when the handset is picked up.