During the instrument cluster work to replace the failed odometer gear, I replaced all the light bulbs with 5050 LED inserts, so I've got all the cluster backlighting back!
like these:
When the key is first turned, all the cluster indicator lights are lit at full brightness for a 1-2 seconds, as they should. So, that's good.
Unexpectedly, some of the LEDs in the lower row of "trouble indicator lights" are dimly lit when even when the trouble signal is not active.
I guess there is some small Voltage present on some of those light sockets that was never enough to get the light bulb filaments to glow, but it's enough to get an LED to glow a little?
Ever heard of this before? Is this to be expected?

The camera in my phone is exaggerating the brightness of the lights.
To my eyes, the lit lower row indicators are dimly lit.

 

I know LED headlight bulbs run at full brightness on half voltage. It is more likely a slight ground leak that is enough to light those bulbs.

 

Is this something that other people have reported when switching the instrument cluster from light bulbs to LEDs?

 

There are lots of issues changing bulbs to LED in non LED cars. From blinker speeds to daytime running light issues. Yes they are more efficient, but most cars look at electrical load to determine bulb integrity.

 

Yes, I experienced and solved "hyper blink" when changing the turn signal bulbs to LEDs on my Ford Ranger.
But, I've never seen my 1994 Saturn SL2 do the "hyper blink" in the 31 years I've owned it.

 

It's all circuitry dependent.