Assembly Parts List For: 131-9D (APU) Part Number OEM PN Description Solution Type In Stock 3876255-2 Switch DER Repair 3881052-1 Switch DER Repair 3881052-2 Switch DER Repair 3888000-7 Exciter, Ignition Repair 9049300-2 Ignition Exciter Repair 3876255-2Switch 3881052-1Switch 3881052-2Switch 3888000-7Exciter, Ignition 9049300-2Ignition Exciter Submit a PMA Development Request