Get a test lamp or a voltmeter and see if power is applied to
the lamp connectors on the low-beam contact, when the switch is in the
low-beam position. If not, look for a burnt fuse.
And, yes, both CAN burn out at the same time. BTDT.
Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here.
All logos and trade names are the property of their respective owners.