The only base type for Wrangler reverse lights is BA15S and no other. Every driver must ensure optimal work of reverse light in Jeep Wrangler 2.8 and any other vehicle. In backup light Jeep installed long lasting small bulbs for cars with engine code ENS. If you own Jeep Wrangler, make sure the backup lamps work properly. Of course, standard voltage of 12 V is used and power must stay near 21 W. It ensures safety not only for 2001 model year vehicles with motor at 4.0.
The first thing to do is purchase 12 V light bulb with fitting base BA15S. Make sure that for S01 model number car with 4.0 motor you bought exactly 21 W light bulb. You may avoid any troubles with 1993 Jeep Wrangler lights going to service station. It might be hard for Wrangler 4.0 owners in Jeep’s production to replace the lamps.