I just bought a 2000 Accord EX V6 and the instrument lights didn't work from the start. Through this website I found that the issue is the MCU or Multiplex which I replaced, but when I replaced it the instrument lights still didn't work. And, also, the radio, headlights and taillights stopped working since I did that. I tried reinstalling the original MCU, but the same current problem is still there. Yes, I disconnected the battery before working on the fusebox. Could there be a short somewhere? I took it to a local shop here and they had the car for 2 days. They told me there was a recall on the dimmer switch for the 2000 accord? I can't find anything online that states that. I think they honestly, just couldn't figure it out. I may have to take it to the dealer which I can imagine could run up to a grand to fix. If anyone has been in this situation or knows what it can be; please help. I will appreciate any input anyone may have. Thank you all in advance.

 

When you put back in the original MCU, did the radio, headlights, and taillights start working? I wasn't sure by your description if that is the case.

Check all 3 fuse boxes for blown fuses. The one under the hood, and the two on both sides of the cabin.

To test, you are going to need a volt meter and a shop manual for your car. The inputs for the dimmer switch, the multiplex control unit, and the headlight switch are good places to start.

The Haynes manual may have the inputs to test on your V6. It isn't a bad investment (~$20 at any parts store). The shop manual is better, but more expensive.

 

Yes, now even with the original MCU they still would not come on. I will check the fuses tomorrow. I do have the hayes manual; I will go over it now. Should I disconnect the battery to check the fuses?

 

You don't have to disconnect the battery to pull a fuse.

 

Okay, I checked all the fuses; driver/passenger/underhood, and they all have power. I do not get power at the headlight switch on those two cables there. Also I don't get power to the cable at the headlights. Please advise, thanks.