Join Date: Mar 2002
Location: California Central Coast
The brake light is on one circuit with two switches, so the problem is probably not due to your new taillight assembly. Likely causes are disconnected wires at the front brake lever, a disconnected connector where the wires from the lever join the wiring harness, or a bad switch in the lever.
First check the wires at the lever. If one or both is disconnected, reconnect and test. If they're securely connected, remove and short them. If the brake light then works, the switch may be faulty. If it doesn't work, look for a wayward connector downstream.