00 Accord Dome light issues/rear door lock issues
 

Couple of issues here that I hope to get some help with. I own a 2000 Honda Accord Special Edition. And the dome light works sometimes. The map lights work perfectly as do the door lights. But the dome light only works when it wants too. I have found no corrosion on the terminals of the dome light or at the map light terminals.And the bulb is good. When it does work it works perfectly for a couple days then its gone. Even changing between the "on" and "door" position I get nothing.


Also the rear door locks will not operate with either of my remotes or the locking switch on the door. I have to manually lock the 2 rear doors but the front 2 door locks work perfectly.


Thanks for your time and help.

The issues may be related or totally separate issues.

1. The ceiling light (aka dome light) have dual functionality; (1) turns on if manually switched to ON, or (2) turns on if door opened. Because the ceiling light have "dual functionality" there are two separate ground sources involved in the circuit. (1) When ceiling light is switched to ON, the light switch get its ground source from the base of the unit. (2) If a door is opened, the light switch gets the ground source from the door switches via wiring that goes through the Passenger side Multiplex Control Unit (MCU) located at the passenger side fuse/relay box and onward to the ceiling light. – All the individual doors switches (at each door) are wired into the passenger MCU.

The issue may be due to :

• Faulty passenger MCU
• Intermittent open (break)in the Blk/Wht wire for the ground source (-) coming from the MCU to the ceiling light. -- Less likely.
• Intermittent open (break) in the Wht/Blu wiring for the power (+) coming from passenger side Fuse No. 11 (7.5A). -- Less likely.
• Since the ceiling light doesn't turn on when switched ON, there can also be an issue with the ceiling light itself and/or the previous items mentioned.

2. The rear door locks not working may be due to:

• Faulty door lock actuators (at each door) -- you can apply battery power (+) and body ground (-) to motors to test individually.
• Faulty passenger MCU (circuit for lock and unlock runs through passenger MCU).
• Wiring

Thanks for the info, I will get the passenger MCU checked. Since it works sometimes. When it decides to work, it works as it should. Open doors and with the switch. but it a rare occasion for it to work.