sajin

I decided to install some LED strips where your feet go. I tapped into the light for the dome so the LED strips would light up when the door opens and gradually dim when you close the door and unlock/lock the car. The location where I tapped into was passenger side interior/courtesy plug. The first strip I installed work flawless. I got a bit cold and turned the car on before I started to install the second strip for the driver side. I ran the wire, and like an idiot, I cut the wire to shorten the extra slack with the car on and door open (strip/dome light on). The lights flickered when I made the cut and thought nothing of it. Finished installing the second LED strip and it was beautiful!


When I closed my doors, the lights never turned off... I even turned off my car and locked it and the lights would still stay on (LED strips + dome). I figured it was from when I shorted the connection. I checked the fuses on passenger side and under the hood. All were fine. Using a voltmeter on the LED strips, they are receiving full 12 [V] when they should be receiving 0. I took off the strips and the problem still persisted with the dome light. Did some troubleshooting and after pulling out the 40 [A] fuse labeled 'BACK UP. ACC" under the hood, the dome light now is only receiving ~5 [V] ALWAYS when left in the middle on the slider, aka controlled by the dimmer circuit or whatever it is controlled by. It receives 12 [V] when set to on or off.

My thoughts are that the problem lies with whatever controls the dimmer function for the dome. I have no idea how to check the fuse for the dimmer because there is no fuse for the dimmer in the fuse box under the hood, it's an empty slot with no slits to enter a fuse but the box says it has a 7.5 [A] one. Anyone have any help or ideas as to what my problem is and how to fix it?

The vehicle is a 2001 Accord V6.

holmesnmanny

Sounds like whatever relay controls that light is stuck on. You need to find the relay and test it.

tech8

Power (+) via Passenger side Fuse No. 11 (7.5A) to the front passenger courtesy light is always hot. The courtesy lights are negative (ground) trigger. When the front passenger door is opened, the ground is supplied from the front passenger door switch to turn on the courtesy light.

sajin

When all doors are closed, it should not have ANY voltage supplied to it. Reguardless, its always at 5 volts. Whether door is open or closed... Or whether car is on or off... My battery would die if I left it in the "neutral" mode

tech8

The ceiling light has dual functionality; (1) turns on if manually switched on at the ceiling light, and (2) works if a door opened. Because the ceiling light has "dual functionality" there are two separate ground sources involved in the circuit. (1) When the ceiling light is switched manually, the light switches gets its ground source from the base of the unit. (2) If a door is opened, the light switch gets its ground source through wiring coming from the Passenger and/or Driver’s Multiplex Control Unit (MCU). – All the individual doors switches (at each door) are wired into the either the Passenger MCU or Driver MCU.

For the ceiling light, there is always positive voltage on the Wht/Blu wire whether the doors are open or closed (as long as the battery is connected). The circuit is not complete until the ground source is provided when a door is opened or the ceiling light switch is manually switched on.

Similarly, for the door courtesy lights, there is always positive voltage on the Wht/Blu wires for the respective door courtesy light. The respective door courtesy light circuit is not complete until the ground source is provided when the respective door is opened (in which case the door switch closes the contacts to allow the ground source).

Your issue may be due to how you wired in the LEDS into the circuit or a short somewhere.

toycar

^^^
This

sajin

Well after some help from other forums, the problem was determined to most likely be the passenger MCU (Multiplexer Control Unit). Did some e-bay searching and found a seller who had a half off sale. Lucky me, they were located in Houston, TX., which is where I live. I made a quick trip there and picked one up for 25 bucks. Replaced the one I shorted out and all works as normal again, even the LED strips!