This 2005 Acura RL came in with the complaint that the battery would go dead if the car sat parked for more than three days straight. The battery had been replaced a couple of times already. I first connected a jump box connected in parallel to the battery before installing the meter as shown below. You cannot see it but the black lead is installed in the COM socket and the red lead is installed in the 10A socket. The dial is set to read DC amps. After an hour there is still a .23 amp drain on the battery.
Because I have been down this road before I consulted a wiring diagram first to see which fuse supplies battery power to the HFL module (Hands Free Link). It turned out to be fuse number 5 in the driver’s side under dash fuse box. Pulling the fuse removed the drain. Pulling the fuse will also activate the anti theft feature in the radio so do not pull it or fully disconnect the battery unless you have the reset codes.
Testing across the fuse terminals had shown a 2.3 millivolt drop confirming there was a drain on that fuse. Sorry that I could not take a picture of this test. Just not enough room and awkward angles to work with.
I looked in my component locator system and found that the HFL module is located behind the right kick panel area. I started by pulling down the passenger side underdash hush panel. It is just snapped into position with two alignment pegs at the firewall edge.
Disconnected the harness connector for the courtesy light and removed the panel.
Lifted the inside edge of the rocker trim panel to begin releasing the clips.
Worked my way from the front to the rear of the trim panel.
Pulled the door seal away from the kick panel.
Pulled the kick panel loose from the body. Note the two clips that secure the panel to the body. Those rarely come out and stay in the panel. I had to remove those separately and reinstall them into the kick panel.
Now if you look above the passenger side interior fuse box location you will see the lower left corner of the HFL module. It is secured to the body with one 10 mm nut which is a little bit of a pain to remove. Not even sure if it has to be removed to disconnect the green harness connector but I wanted to make sure you had a good view of the actual part.
Since the battery had been connected during all of my testing the HFL module was warm to the touch.
With the HFL module disconnected the standby drain dropped to an acceptable .03 amps.
As in most cases the vehicle owner never uses that system so they elected to leave it disconnected. I did leave it installed in the car but electrically disconnected.