Hey everyone, I drive an 1998 v6 3.0 honda accord. When I first got the car , I couldn't roll down any of the windows except for the driver side window using the main window regulator. But I can roll down each window individually using the window regulator for that window. My dash lights have also stopped working. I have replaced the multiplexer, replacing it allowed me to be able to unlock all the doors from the driver seat. But it haven't appeared to change anything else. Also, my keypad to unlock the doors only work sometimes , and I've replaced the battery in the keypad. Can someone please help me. Thanks in advance.

 

1. What trim level is your Accord, LX or EX? The circuit for the dash lights is slightly different between the two.

2. If the power windows all work at each switch, except for at the driver's door master switch, then it may be a problem with the driver's door multiplex control unit.

Honda TSB 98-071

3. The keyless receiver unit is part of the passenger multiplex control unit (MCU). There may or may not be an issue with the unit. - You may want to do some test before replacing any parts though.

 

Alright , thanks. And I think it's an LX. But I'm not for sure , so can you give me both the LX and EX method for the dash lights?

 

The troubleshooting would not be exactly the same for the circuits, and I would be thinking up the procedures based on the circuit diagrams. The troubleshooting would be where I write up some steps and you would perform the tests and post results. From the results, I may write up some more tests based on the result and we would try to further narrow down the area of problem. We would try not to replace a part without testing.

If your Accord V6 has an OEM moonroof, you have an EX. If there is no moonroof, you have a LX.

 

Good TSB there..they sure are handy members..look them up here in the forums..

 

Thanks for the advice. I have an EX, what's the trouble shooting procedure that I need to follow?

 

1. First check Fuse No. 10 (10A for sedan) located in the passenger side fuse box.

2. Other than the dash lights not working, with the combination light switch turned on, does the following work?

• Vanity mirror lights
• Glove box light
• Clock

3. Was the multiplex control unit (MCU) you replaced (I assume at the driver’s dash side fuse/relay box) new or used?

4. See this video and follow the instructions to see if it may still be due to the MCU; does your dash light work with the jumper wire?


5. If you followed the video instructions and tried the jumper wire and the dash lights still doesn’t work, then we move on to our first test. Note: This first test is to narrow down the area of the problem and further tests will be performed after you post your results. – the first test does not necessarily mean the tail light relay is faulty, etc.

On your EX, you have a tail light relay located on the passenger side. Power for a lot of various small lighting has to run through this relay. If you have a voltmeter, you can test a few wires there to diagnose to narrow down the area of issue(s). You will want to backprobe a few wires. Backprobing is either using a backprobe set or using a thin needle or something and making contact with the metal terminal of the connector without piercing the wire in the back of the still connected connector. Care must be taken to ensure that the wiring does not get damaged. You can use something like a T pin, available at Walmart, etc., and backprobe. These pictures are just to give a picture of the concept of backprobing without piercing any wires.

• At the tail light relay (with it stilled plugged in), with the voltmeter’s black lead touching chassis/body metal ground, use the voltmeter’s red lead to backprobe the Red/Blk wire at the tail light relay. There should be voltage at the Red/Blk wire with the combination light switch turned on (i.e., parking lights or headlights on). (Red/Blk wire should be a wire with red color insulation and a blk stripe.)

• If no voltage in above procedure; with the voltmeter’s black lead touching chassis/body metal ground, use the voltmeter’s red lead to backprobe the Red/Grn wires at the taillight relay with the combination light switch on. There will actually be two separate Red/Grn wires there, one Red/Grn wire (terminal connector 2 pin) is coming from Fuse 10 in the passenger fuse box, the other Red/Grn wire (terminal connector 5 pin) will be coming from the driver’s multiplex control unit. There should be voltage.

Post the results of your testing and I will give further instruction on what to test next. Do not replace any parts yet. It may just need some wiring repaired.

 

All of the other lights work. I also can control all of my other windows from the driver side now(thanks) . The multiplexer that I got was used. I did the paper clip trick that the dude did in the video, and at first my dash lights would come on, but the fuse would blow. So I inserted a 20 amp fuse in the slot instead of the 10amp. Once i did this, I noticed that the dash lights would stay on , but the paper clip became a blazing orange color and it started smoking, what could that mean?

 

If the fuse blew, it most likely mean you have a short in the circuit; a short is an accidental connection of a wire to ground or to another wire or the short can be a component contacts are shorted.

Putting in a higher amperage fuse was one of the worse things to do. It can and may cause damage to wiring and components; and even start a fire. There may be further damage now as a result.

 

Yea, I thought about that after I did it, so I went back and checked everything. Everything appears to be fine. I removed the paper clip and now it's back to its normal function of having no dash lights. Which circuit should I start off with checking?