No change in brightness between DRL and Low Beams
Asked by Mike Oct 10, 2022 at 12:06 PM about the 2006 Toyota Corolla LE
Question type: Maintenance & Repair
When I turn on the headlights, the Low Beams do not increase brightness from
the DRL intensity. Is this related to the DRL relay or is there another relay for
the Low Beam circuit I should look at? I've checked all my grounds, replaced
the bulbs and installed new headlight assemblies with clear lenses.
3 Answers
Check the shop manual, some vehicles do not drop voltage for DRL and just use the low beam circuit for the DRL system so there won’t be any change in brightness. It’s that way on both my vehicles.
Sounds like a problem with the ambient light sensor. The sensor is usually on the top of the dash. Usually low resistance on the sensor will indicate light (daylight) so the DRL will remain on. High resistance indicates darkness which will switch on the headlights. When you find the sensor, for testing purposes, unplug it. If the headlights come on, you found the problem. Hope that helps! Jim
