System Description

WARNING: This page is about a different car, the 2004 Infiniti I35. However, it is still accessible from the selected car via links, so may be relevant.

The rear window defogger system is controlled by the smart entrance control unit. The rear window defogger operates only for approximately 15 minutes.

Power is supplied at all times

to rear window defogger relay terminal 3
through 20A fuse [No. 7, located in the fuse block (J/B)] and
to rear window defogger relay terminal 6
through 20A fuse [No. 4, located in the fuse block (J/B)]
to smart entrance control unit terminal 49
through 10A fuse [No. 13, located in the fuse block (J/B)].

With the ignition switch in the ON or START position, power is supplied

through 10A fuse [No. 10, located in the fuse block (J/B)]
to the rear window defogger relay terminal 1 and
to smart entrance control unit terminal 27.

Ground is supplied to terminal 32 of the rear window defogger switch (built-in A/C auto amp.) through body grounds M9, M25 and M87.

When the rear defogger switch is turned ON, ground is supplied

through terminal 31 of the rear window defogger switch
to smart entrance control unit terminal 14.

Terminal 37 of the smart entrance control unit then supplies ground to the rear window defogger relay terminal 2.

With power and ground supplied, the rear window defogger relay is energized.

Power is supplied

through terminals 5 and 7 of the rear window defogger relay
to the rear window defogger and
to terminal 30 of the A/C auto amp.

The rear window defogger has an independent ground.

With power and ground supplied, the rear window defogger filaments heat and defog the rear window.

When the system is activated, the rear window defogger indicator illuminates in the rear window defogger switch.