Peterbilt 389 Dome Light Bulb Size

Additional Notes

• The Peterbilt 389 uses the 211-2 bulb for its dome light across the 2011-2017 model years.
• The 211-2 is an ANSI-standardized bulb, meaning its physical and electrical specifications are governed by a recognized North American standard shared across the United States and Canada.
• The 211-2 belongs to the festoon bulb family, a cylindrical form factor that mounts by pressing both ends into spring clips rather than using a screw or bayonet socket.
• The 211-2 has a length of 41mm, which is a defining fitment factor for festoon bulbs, as the spring-clip housing must match the bulb length precisely to maintain secure contact.
• The 211-2 uses an SV8.5 base, a designation that refers to the 8.5mm cap width on each end of the festoon body.
• The bulb operates at 12 volts, consistent with the standard electrical system voltage found in most commercial trucks.
• The 211-2 carries a 12-watt rating, which reflects its power draw at the rated voltage and determines the current load placed on the dome light circuit.
• The 211-2 and 212-2 are closely related festoon types that are sometimes referenced interchangeably in fitment guides, though the 212-2 differs slightly in wattage, making direct substitution a consideration that warrants attention to the socket and circuit specifications.