LSI-008 Rev B
Page 2 of 3
Note: The following procedure can be accomplished with the MCU mounted on the aircraft, or with
the MCU removed.
1.)
Remove cover from MCU.
2.)
Inspect the label on the alternator control module (A). If the part number on the module is
AC2101 and the serial number of the module falls between 195601 and 205400, it should be
replaced with a new AC2101, revision I.C. 4 or above, per this procedure. If the part number
is AC2100 or the serial number falls outside this range, no upgrade is necessary.
3.)
If MCU is on aircraft, disconnect the alternator power cable from the AC2101 bus bar by
removing the nut and bolt (B).
4.)
Disconnect the cable plug from the AC2101 (C). The plug latch must be lifted to disengage.
5.)
Remove the nut and washer securuing the AC2101 bus bar to the alternator contactor (D).
6.)
Loosen and remove the two screws securing the AC2101 to the base (E).
7.)
Remove the AC2101 from the MCU
8.)
Install new AC2101 (revision I.C. 4 or above) over the alternator contactor post and onto
MCU base.
9.)
Install two screws to secure AC2101 to base (E). Assure that ground wire lug is under one
screw (F). Tighten screws to 12 in-lb.
10.)
Install nut and lock washer securing AC2101 bus bar to alternator contactor (D). Tighten nut
to 35 – 45 in-lb.
11.)
Reconnect the cable plug to the AC2101 connector (C). Assure plug is fully seated by
observing latch engagement.
12.)
If MCU is on aircraft, reconnect the alternator power cable to the AC2101 bus bar (B) with
nut, bolt and washer. Tighten nut to 35-45 in-lb.
13.)
Replace the cover on the MCU and secure in place with the screws.
14.)
Assure that aircraft log book entry is made identifying that MCU has been upgraded per this
procedure.
