This is a followup to a thread that I posted, called "Accessing switched (accessory/ACC) power for aftermarket devices). It's desirable to tap into "switched" (not always-on) circuits like this, so your aftermarket gadget doesn't drain your battery.
That thread gave details re. how to tap into the front accessory power socket circuit to hardwire devices. However, it missed the forest for the trees. Others have pointed out a much simpler way: some of the fuse positions, which are easily tapped into with a mini-fuse tap, are switched. In fact, some of the unused fuse positions are switched (e.g. position 2).
To be a little more complete, I looked at the circuit diagrams from Service Express and labeled each fuse with what kind of relay controls its power. The list is below.
KEY:
If relay is any of the "IG" relays: fuse position is "hot" only when car is fully on.
If relay is any of the "ACC" relays: fuse position is "hot" when car is either in ACC mode, or fully on.
If relay is ALWAYS ON: runs directly off the 12V battery, so fuse position is "hot" even when car is off. Doesn't mean the entire circuit works when car is off (there may be other interrupting relays down the line).
This is a GUIDE, and may contain errors -- verify! Note that the fuse tap size seems to be "mini" fuse, to fit properly. Note also that there is a right, and a wrong, way to put in a fuse tap IF it is into a circuit already being used for another purpose.
Short version: Only position 2 is both ACC and unused. There are 2 unused IG-switched positions, which are probably just as good (how often do you sit in ACC mode only anyway?) There are two unused always- on. Full fuse-to-component map from Service Express is attached.
C01: ACC-Audio, body control module, accessory socket relays:
C02: ACC- NOT USED
C03: Ig1B -PCM
C04: Ig1B –SBW Shifter Control Module
C05: Ig1B -Fuses E1-E3 in under dash subfuse box B
C06: Ig1B - Front passenger’s airbag cutoff indicator
C07: Ig1B - Acoustic vehicle warning, climate control, reverse relay
C08: Ig1A – body control module, fuel tank, etc.
C09: Ig2 – seat heater relay, some power mirror
C10: ALWAYS ON (ACC relay comes after
C11: Ig – NOT USED
C12 ALWAYS ON – R side power door locks
C13 ALWAYS ON – L rear power door unlock
C14: ALWAYS ON – Rear L power window
C15: ALWAYS ON – Front passenger power window)
C16: ALWAYS ON – trunk opener)
C17: Ig1B - Parking pawl actuator
C18: ALWAYS ON – NOT USED
C19 :ALWAYS ON? (Washer motor control unit)
C20: IG—NOT USED
C21: Ig1A - Sensors
C22: IG2- Body control module Ig2
C23: ?? —not used (per fuse map; but there is 10A fuse in it)
C24: Ig1B- Front camera
C25: ALWAYS ON – door locks
C26: ALWAYS ON – door lock
C27: ALWAYS ON – windows
C28: ALWAYS ON – windows
C29: ALWAYS ON – ACC sockets (relay comes later)
C30: ALWAYS ON – interior lights
C31: ALWAYS ON – Seats
C32: ALWAYS ON – Seat heater; relay comes later
C33: ALWAYS ON – Seats
C34: Ig1A – EPS, brake relay, etc
C35: ?? - SRS
C36: ALWAYS ON –NOT USED
C37: ALWAYS ON – Battery charge module, charge door
That thread gave details re. how to tap into the front accessory power socket circuit to hardwire devices. However, it missed the forest for the trees. Others have pointed out a much simpler way: some of the fuse positions, which are easily tapped into with a mini-fuse tap, are switched. In fact, some of the unused fuse positions are switched (e.g. position 2).
To be a little more complete, I looked at the circuit diagrams from Service Express and labeled each fuse with what kind of relay controls its power. The list is below.
KEY:
If relay is any of the "IG" relays: fuse position is "hot" only when car is fully on.
If relay is any of the "ACC" relays: fuse position is "hot" when car is either in ACC mode, or fully on.
If relay is ALWAYS ON: runs directly off the 12V battery, so fuse position is "hot" even when car is off. Doesn't mean the entire circuit works when car is off (there may be other interrupting relays down the line).
This is a GUIDE, and may contain errors -- verify! Note that the fuse tap size seems to be "mini" fuse, to fit properly. Note also that there is a right, and a wrong, way to put in a fuse tap IF it is into a circuit already being used for another purpose.
Short version: Only position 2 is both ACC and unused. There are 2 unused IG-switched positions, which are probably just as good (how often do you sit in ACC mode only anyway?) There are two unused always- on. Full fuse-to-component map from Service Express is attached.
C01: ACC-Audio, body control module, accessory socket relays:
C02: ACC- NOT USED
C03: Ig1B -PCM
C04: Ig1B –SBW Shifter Control Module
C05: Ig1B -Fuses E1-E3 in under dash subfuse box B
C06: Ig1B - Front passenger’s airbag cutoff indicator
C07: Ig1B - Acoustic vehicle warning, climate control, reverse relay
C08: Ig1A – body control module, fuel tank, etc.
C09: Ig2 – seat heater relay, some power mirror
C10: ALWAYS ON (ACC relay comes after
C11: Ig – NOT USED
C12 ALWAYS ON – R side power door locks
C13 ALWAYS ON – L rear power door unlock
C14: ALWAYS ON – Rear L power window
C15: ALWAYS ON – Front passenger power window)
C16: ALWAYS ON – trunk opener)
C17: Ig1B - Parking pawl actuator
C18: ALWAYS ON – NOT USED
C19 :ALWAYS ON? (Washer motor control unit)
C20: IG—NOT USED
C21: Ig1A - Sensors
C22: IG2- Body control module Ig2
C23: ?? —not used (per fuse map; but there is 10A fuse in it)
C24: Ig1B- Front camera
C25: ALWAYS ON – door locks
C26: ALWAYS ON – door lock
C27: ALWAYS ON – windows
C28: ALWAYS ON – windows
C29: ALWAYS ON – ACC sockets (relay comes later)
C30: ALWAYS ON – interior lights
C31: ALWAYS ON – Seats
C32: ALWAYS ON – Seat heater; relay comes later
C33: ALWAYS ON – Seats
C34: Ig1A – EPS, brake relay, etc
C35: ?? - SRS
C36: ALWAYS ON –NOT USED
C37: ALWAYS ON – Battery charge module, charge door
