I drive a 2000 Honda Accord EX V6 Coupe with the automatic transmission. I'm at about 148,500 miles. My problem is the backlights for all of the instruments (instrument cluster, climate control cluster, clock, radio cluster) have started to flicker with the rev of the engine (they dim and brighten rapidly) while I roll forward in idle up until I accelerate to around 1500 RPM. I was told it could be the alternator/voltage regulator so I replaced that, but it didn't fix the problem. Are there any other things I can check?

Possibly related, my D4 light in the selection cluster to the right of the gas gauge does not always come on when the car is in drive, and the selector lights to the left of the shifter also do not always work. Any help or diagnostics would be appreciated.

 

What did the test of the alt voltage at idle show? You said you replaced it but didn't say what the tests showed on the old vs. the new?

 

The last time i had that exact issue, it was the alternator.. you're saying you replaced the alternator and still having the issue?! Check your grounds maybe and clean off your battery terminals

 

Well, before I replaced the alternator, my test told me I was holding at 1300 but after running for about 30 seconds it would sink down to 1200, which is normally a charging system, alternator, voltage regulator type issue. So I thought it would fix the problem but it didn't. The new alternator gives me a steady output of 1400 with maybe a slight drop after running for a while.

Battery terminals and grounds are clean and tight, still having the problem.

Update: It only happens when my dimmer switch is at the lowest setting. I know the easy remedy would be to keep the variable resistor at its highest brightness setting and that does fix the problem, but the bright dash lights hurt my eyes and I like to keep them dim.

Is there some sort of remedy for a faulty variable resistor or any other ideas from you guys on what the problem could be?

 

There has to be a resistor associated with the dimmer assembly. Might be best to call Honda and ask them what the part number is. Then you can look it up and find out where it is. Then you can pull one from the junkyard or atleast test it.

I just looked and I can't find it yet in any illustration.

 

swap the whole dimmer assy

 

Any hints on what to look for for the dimmer assembly? Is it just the black box in the driver's side fuse panel?

 

The dash light brightness controller (dimmer) is part of the gauge assembly.

You can test it by taking the gauge assembly out, then unplug Connector B (22P connector).

Measure the resistance between terminal B4 and B5 while rotating the adjusting dial. Resistance should vary from 0 to 20,000 ohms as the dial is rotated.