Is it normal for the backlight on the cluster (speedo, tachometer, etc) to dim slightly sometimes? The car is at a steady ~900RPM at idle, but sometimes the light dims down for a split second, then comes back up, repeat a few times, then it will be fine, but might repeat the cycle a minute or so later.

Can't say I've noticed it before. And I'm not doing anything while this happens, no wipers, no turn signals, no fan, even shut off the radio.

I recently connected my boost gauge bulb to the rheostat, but doubt that would be the cause, and I *think* I saw that pulsating once or twice before doing this.

Are the regulator/rectifiers or other electric parts on Evos susceptible to failure? Could it be loose battery terminals?

 

Honestly I'd say it could be your battery is weak and not holding a charge, belt is lose causing the the alternator to not charge fully, or lose connections. Start with the battery and work your way back. Easy fix hopefully.

 

Hmm, I bought the battery probably less than 2 years ago. I guess I'll slap a voltage gauge on the terminals to compare to the dimming.

But definitely not something that's common to the Evo right?

 

If you have a sub or are playing your stereo real loud could do this too.

 

Should just be caused by the alternator not supplying enough current right away when the car requires a extra few amps. It cant anticipate a usage spike so it plays catchup. As you car requires more power it pulls from the system and the battery and then the alternator cycle increases and it takes up the slack.

Basically its normal as long as the pulses arent 2 or more seconds long dim to bright. If its dim for a relatively long time i'd say weak alternator or battery. Til then nothing to really worry about.

 

+1, some of my previous cars will do something similar