Why daytime running lights work on 1996 Chevy sliverado?

A 1996 Chevy Silverado doesn't have daytime running lights (DRLs) as a standard factory feature. DRLs were not mandated in the US until later model years. If your 1996 Silverado *appears* to have DRLs, it's likely one of these:

* Aftermarket Modification: Someone added them after the fact. This is a common modification. They might be wired to come on with the ignition, mimicking factory DRLs.

* Misunderstanding of Headlights: You might be mistaking the headlights themselves for DRLs. If the headlights are low-beam only (not high beam) and are on when the ignition is on, that's not necessarily DRLs; it could be a design choice or a quirk of your vehicle's wiring.

* Faulty Wiring: There's a possibility of a wiring fault causing some lights to turn on unexpectedly with the ignition.

To determine what's actually happening, check your Silverado's wiring and the components installed. If you added them yourself, you know the answer. If not, it's most likely a modification by a previous owner or a wiring issue. An automotive electrician can quickly diagnose it.