Dimmer switch revisited

The dimmer switch which seems to be defective or doesn’t work the way you expect. Some say you have to turn the switch to the max until you hear the “click” and hold for a few seconds then it will work. Others say that you have to push the wheel and turn while keep pushing the wheel. Here is what I found:

In order for the dimmer switch to work, you have to meet 2 conditions:

1. The ambient light has to be somewhat dark.
2. The light switch must NOT be in the OFF position.

Condition 1 I found out by accident when I drove pass under the bridge and suddenly all the instrument panel turned dark! I didn’t have time to do any adjustment, so the next test I did was when I came back home and pulled my car into my garage. The night before I already tried but no luck but by now I realized that the light in my garage was on. Sure enough when I turned the garage’s light off and turned the dimmer wheel all the way down then turn the light switch to AUTO, the instrument panel was totally dark except the very fade mhp number. Next I turned the light switch to the ON and PARK positions and the dimmer still worked fine but when I turn the light switch to the OFF position, the instrument panel was a the maximum brightness and the dimmer had no effects. Note that the dimmer also dimmed the screen, the display under and along both sides of the screen as well as the 2 switches to the left of the dimmer. While playing with the dimmer , I found out that when you turned the light switch to OFF position the dimmer still dimmed the POWER switch slightly! So when you think your dimmer switch doesn’t work, just turn it up and down then look at the green illumination of the POWER switch, if the brightness changes then your dimmer must be fine.

I think the reason for condition 2 is that when people turn the light switch to OFF, then it must not be dark out for sure so there is no need for the display to go dim. The brightest level of the display won’t bother the driver’s eyes unlike at night time when the display is too bright and it may cause the glare to interfere with the vision through the windshield. And this is why the dimmer supposedly work when it is dark out only.

If you can’t wait until dark, just cover the light sensor (the little black dome on the dash to the right) with something that is not translucent and do the test. I set my light sensitivity to position 2 so you may want to try others until you find the right spot.