How can I get started on fixing this?
Here is an image of a dual-beam bulb. Note that it has 2 filaments as labelled:
You need to check if one of the filaments has fried. If the filament isokay for both high and low beam then you will need to replace your relay
- Test the relay (https://www.youtube.com/watch?v=ire7vyDqelg)
- Order the relay if not good
- Replace the relay
It is common for low beams to get used more than the highs, so it might be as simple as checking and changing the bulbs. Failing that, start by checking the fuse(es). If neither of those moves solve the problem, here are a few questions and answers that will probably help if you get it sorted out:
Also, take a look at the Related links on the right, there is often good information there.