To adjust the duration, you'll need to experiment with the switch itself. Many times, there's a simple on/off setting and potentially a way to hold it in a position to change how long it stays on (though the manual might not detail specific timings).
Try these steps:
1. Locate the overhead console: This is usually located near the rearview mirror.
2. Find the dome light switch: It might be a simple rocker switch or a rotary dial.
3. Experiment with switch positions: Try holding the switch in different positions (sometimes a brief press or hold changes the timing). Observe how long the light stays on after you close the doors. You may need to repeat this multiple times to figure out the behavior.
If you find no way to adjust the timing via the switch itself, it's likely the van's dome light system is simple and doesn't offer adjustable timing. The light may stay on until the door is opened again, or there could be a fixed timer duration built into the circuitry that cannot be altered.
Consulting your owner's manual might provide more clues, though it's unlikely to be very specific in this regard for a 1999 model.
