Headlight intensity in auto mode

[edge3333]

According to my 2010 Highlander User's Manual, the headlights should run at reduced intensity during the day when in the auto mode. I've noticed that the intensity is always the same whether it's day or night. The only difference is that the yellow side lamps turn on when the system senses that there is insufficient daylight. I've proven to myself that the intensity is always the same by "tricking" the light sensor in a dark garage using a high intensity spotlight pointed at the sensor which will cause the lamp display on the dash to turn off.

Has anyone out there experimented with their Highlander to see if the headlight intensity is actually reduced during daylight hours?

[sweeneyp]

The DRL's are the lowbeam circuit and they run at something like 80% max power (my toyota docs say "8.47-12.6V" range of power for the DRL (opposed to 13.5'ish volts at full power). Its pretty close to full power. Most cars with DRL's run like 6 volts in the high beam circuit so its easy to see, I don't know why Toyota decided to use the low beam though (but that does force them to up the power to be visible during the day).

So they are going to appear similar, but it should be just a tad less (enough to not drastically shorten bulb life). I don't think its anything to worry about.

[edge3333]

Originally Posted by sweeneyp

The DRL's are the lowbeam circuit and they run at something like 80% max power (my toyota docs say "8.47-12.6V" range of power for the DRL (opposed to 13.5'ish volts at full power). Its pretty close to full power. Most cars with DRL's run like 6 volts in the high beam circuit so its easy to see, I don't know why Toyota decided to use the low beam though (but that does force them to up the power to be visible during the day).

So they are going to appear similar, but it should be just a tad less (enough to not drastically shorten bulb life). I don't think its anything to worry about.

Thanks for the reply. After experimenting again, I do see a slight decrease in intensity when in the auto mode and simulating daylight conditions.