Power Lumbar Circuit Description w/o A45

Battery positive voltage (B+) is supplied at all times to the lumbar switch from the rear fuse block PWR SEAT circuit breaker.

When the lumbar switch is operated to move the lumbar back, battery positive voltage (B+) is applied via the lumbar back switch contacts, and the lumbar back control circuit to the lumbar horizontal motor. The motor is grounded via the lumbar forward switch contacts and the lumbar back control circuit to the motor. The motor runs to drive the lumbar back, away from the occupant's back, until the switch is released. Moving the lumbar forward works similarly to moving the lumbar back. Except that battery positive voltage (B+) and ground are applied on opposite circuits causing the motor to run in the opposite direction. This action drives the lumbar forward toward the occupant's back.

When the lumbar switch is operated to move the lumbar up, battery positive voltage (B+) is applied via the lumbar up switch contacts and the lumbar vertical up control circuit to the lumbar vertical motor. The motor is grounded via the lumbar down switch contacts and the lumbar down control circuit to the motor. The motor runs to drive the lumbar up until the switch is released. Moving the lumbar down works similarly to moving the lumbar up. Except that battery positive voltage (B+) and ground are applied on opposite circuits causing the motor to run in the opposite direction.