Dimmable LEDs?

[dmorales-bello]

Without having taken into account the dimming function of the OEM rheostat, I swapped the bulbs in my dash instruments to bright white LEDs, the idea being to get brighter and sharper illumination on my instruments. I left incandescent bulbs in the places I wasn't looking to get brighter lights: turn signal indicators, brake indicator, charge indicator, HVAC controls.  The dimmer allows full brightness BUT will dim the incandescent lights more than the LEDs. The change in light intensity in the LEDs is not very noticeable as you turn the dimmer control counterclockwise. Not a problem in my case since I did achieve what I wanted which was crisp white light from my instruments.

[Captain Obvious]

The dimmer allows full brightness BUT will dim the incandescent lights more than the LEDs. The change in light intensity in the LEDs is not very noticeable as you turn the dimmer control counterclockwise.

 

Yup. That's exactly what would happen. The incandescents will always dim just fine, but the fewer of them you have remaining in the system, the less you'll get the LEDs to dim.

 

And by the way.... As far as the dimming function goes, the stuff like the brake indicator, turn signal indicators, high beam indicators... None of those are connected to the dimmer so they don't matter one way or the other. Leaving them as incandescents won't help your LEDs dim. Only the incandescents that are dimmed will matter.

 

On the 78, the only things that are dimmed (besides the gauges themselves) are the hazard switch, the HVAC faceplate, the original radio bezel, and the A/T shifter bezel (if you've got an automatic).

 

So if you've got a manual trans 78 with an aftermarket radio and have already updated the HVAC bezel, then you've only got one tiny dimmed incandescent lamp remaining in your system and that's the one in your hazard switch.