GMC 1996 Sonoma Owner's Manual page 89

When the DRL are on, only your headlamps will be on.
The taillamps, sidemarker and other lamps won't be on.
The instrument panel won't be lit up either.
When
it
begins to get dark, your DRL indicator light
is
a reminder to turn your headlamp switch on. The
other lamps that come on with your headlamps will
also come on.
When you turn the headlamp switch off, the regular
lamps will go off, and your headlamps will change to
the reduced brightness of DRL.
To idle your vehicle with the DRL off, set the parking
brake. The DRL will stay off until you release the
parking brake.
As with
any vehicle, you snould turn on the regular
headlamp system when you need it.
og Lamps
1
':ion)
Use your fog lamps for better vision in foggy or misty
conditions. Your parking lamps or low-beam headlamps
must be on
for your fog lamps to work.
The fog lamp switch is on the instrument panel under
the lamp switches.
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