Driving at night, odometer LED flashes lightly..alt?

[PWGuy]

I was driving my '03 ZTS around the other night. I was stopped at a light and noticed the odometer backlight was dimming when the idle would "spudder" ever so slightly. It is like a very slight, dim light flash that goes in and out with idle.

I just replaced the battery about 4 weeks ago, so I know that isn't the issue.

Any ideas? Alternators known for going bad and causing this as they degrade?

[Sponsor]

[SkyPilot]

The backlight for the Odometer is starting to die, its a fairly common problem, eventually it wont light at all but it will still be easily readable

[PWGuy]

The CEL came on the other evening and it is dimming too, so it isn't the LED bulb itself.

[sailor]

Well, that's not a good thing......

Things to start with:

Get the code read. (free at many parts stores)

Check the voltage with a meter, sometimes having it hooked up while driving helps with diagnosis....

Check idle RPM - low or fluctuating idle CAN be an issue, you don't want to chase charging problems if you actually have an idle rpm issue....

Luck!

(get back with results, someone will make better guesses from the info. you get...)

[PWGuy]

Sorry, the CEL was from me unplugging the DPFE to test it. It's off now but it accidently confirmed the dimming issue I was having.

How do I check the voltage with a meter? Dumb question, I know..

[rsnow]

go back and make sure you have a tight battery connection! with the car running you should have 14 volts from terminal to terminal with a dvom on voltage scale. If ok, you may have a alternator starting to go. Also look at your battery cables and look if the end are melted some, high resistance in the cables cause this an can cause the problems as well.