To "reset" the low tire pressure light on a 1999 Prowler, you simply need to:
1. Inflate your tires to the proper pressure. Check the sticker on your driver's side doorjamb or your owner's manual for the recommended tire pressure. Use a reliable tire pressure gauge.
2. Drive the vehicle. After inflating the tires to the correct pressure, drive the vehicle for a short distance (a few miles) at a moderate speed. The light should turn off automatically once the system detects that the tires are properly inflated. If it doesn't go out after a short drive and you are sure that all the tires have the correct pressure, there may be a more serious issue.
If the light remains on after inflating your tires and driving, there could be a problem with the sensor, wiring, or even a slow leak in one or more tires that isn't easily noticeable. You should have a mechanic check it out.