Lumbar Supports

Power is supplied at all times to the up/down lumbar adjuster relay and the fore/aft lumbar adjuster relay from the SEAT Circuit Breaker through circuit 340. Power is also supplied at all times to the driver seat lumbar adjuster switch from the H SEAT/LUM Fuse through circuit 2040. The up/down lumbar adjuster relay and the fore/aft lumbar adjuster relay, which are grounded at G301 through circuit 750, normally ground both sides of the up/down lumbar support motor and the fore/aft lumbar support motor.

When the driver seat lumbar adjuster switch is set to the up position, voltage is supplied through circuit 387 to the up/down lumbar adjuster relay, causing the up relay to pull in. Voltage is then supplied from circuit 340, through the up relay normally open contacts and circuit 768 to terminal B of the up/down lumbar support motor. Terminal A of the up/down lumbar support motor is connected to G301 through circuit 750, the up/down lumbar adjuster relay normally closed contacts of the down relay, and circuit 767. This causes the up/down lumbar support motor to rotate to raise the lumbar support.

When the driver seat lumbar adjuster switch is set to the down position, voltage is supplied through circuit 386 to the up/down lumbar adjuster relay, causing the down relay to pull in. Voltage is then supplied from circuit 340, through the down relay normally open contacts and circuit 767 to terminal A of the up/down lumbar support motor. Terminal B of the up/down lumbar support motor is connected to G301 through circuit 750, the up/down lumbar adjuster relay normally closed contacts of the up relay, and circuit 768. This causes the up/down lumbar support motor to rotate to lower the lumbar support.

The fore/aft lumbar support works in a similar manner using the fore/aft lumbar adjuster relay and the fore/aft lumbar support motor.

Each motor contains a solid state self-resetting circuit breaker to protect it from overload. Electronic Circuit Breaker (ECB) resistance increases if a motor is overloaded and returns to normal after voltage is removed from the motor terminals.