Daimler Trucks
North America LLC

Customer Advisory Letter

December 6, 2021

CAL FTL 54-021

Subject: Positive Battery Load Disconnect Switch Back-of-Cab (BOC)
Installation
Model: Freightliner New Cascadia vehicles built from August 2, 2021 through December 31, 2021

Our records indicate that you are the owner of certain vehicles, and DTNA has decided to share the following
documentation with you.
Please see the attached work instructions. We hope you find this information helpful.

Customer Advisory Letter

Daimler Trucks
North America LLC

CAL FTL 54-021

December 6, 2021

Subject: Positive Battery Load Disconnect Switch Back-of-Cab (BOC)
Installation
Model: Freightliner New Cascadia vehicles built from August 2, 2021 through December 31, 2021

Overview:
These work instructions cover replacing the battery cable access (BCA), installing a battery load disconnect switch
and bracket at the BOC, and installing a harness between the new BCA and battery load disconnect switch.

Parts:
Part Number

A66-05335-043
A66-01882-002
A66-02293-000
A66-21246-000
910105 008016
910112 008000
23-13759-725
24-01618-002
24-01594-000

Parts Needed
Description

HARN-BCA SOL CNTRL,FPT
MDL-BCA,HL NO/CB W/CNTR, P4
POSTIVE C/O SW W/LOCKOUT
BRKT-BAT,CUT OFF SW,BOC,P4
SCRW HEX FLNG,M8X1.25X30
NUT,HX FLNG MTRC,M8X1.25,CL
SCREW-MACH,M8.0X1.25X25MM,S
LABEL-NOTICE,BATTERY DRAW
LABEL-CUTOFF SWITCH
Fabric Abrasion Tape
Zip/Cable Ties

Work Instructions:

Qty

1
1
1
1
2
2
4
1
1
As needed
As needed

1. Park the vehicle on a level surface, shut down the engine, set the parking brake. Chock the tires.
2. Disconnect the batteries.
3. Remove the three screws that attach the dash cover throttle to the dash and the accelerator pedal assembly
and remove the panel as shown in Fig. 1.

Fig. 1, Throttle Panel Removal
If needed, see Group 60.06, Subject 100 in the New Cascadia Workshop Manual for instructions.

Customer Advisory Letter

Daimler Trucks
North America LLC

December 6, 2021
CAL FTL 54-021
4. Remove the dash cover steering column kick panel as shown in Fig. 2. If needed, see Group 46.01, Subject 110
in the New Cascadia Workshop Manual for instructions.

Fig. 2, Steering Column Kick Panel
5. Remove the electrical bay cover as shown in Fig. 3.

Fig.3, Electrical Bay Cover
6. Remove the seven screws that attach the cover to the dash as shown in Fig. 4, then pull the clips loose and
remove the cover.

Fig. 4, Passenger Side Lower Dash Cover

Daimler Trucks
North America LLC

Customer Advisory Letter
CAL FTL 54-021

December 6, 2021

7. Remove the existing BCA box. Refer to the Group 54.08, Subject 110 and Group 60.06, Subject 100 of the
New Cascadia Workshop Manual for instructions.
8. Install the new BCA box. Refer to Group 54.08, Subject 110 of the New Cascadia Workshop Manual for
instructions.
NOTE: When installing the battery cables on the BCA battery studs, apply a drop of LOCTITE® Blue 242 to
the area of the studs the tightened nuts will overlap. Install the washers and the nuts. Hold the end of each
stud with vice grip pliers as shown in Fig. 5 and tighten each nut with a 13 mm box end wrench to secure
the cable to the BCA. Tighten the nuts 10 to 12 lbf·ft (14 to 16 N·m).

Fig. 5, Gripping the Stud to Tighten the Nut
9. Install the electrical harness.
9.1. Wrap the length of the new harness (part number A66-01937-000) with fabric abrasion tape.
9.2. Route the new harness alongside the main cab harness as shown in Fig. 6. Run the harness from the BCA
box to the front wall grommet located above and to the left of the steering wheel, as shown in Fig. 7.
Use cable ties to secure the new harness to the main cab harness as needed.

Fig. 6, New BCA Harness Routing

Daimler Trucks
North America LLC

Customer Advisory Letter
CAL FTL 54-021

December 6, 2021

Fig. 7, Firewall Pass-Through Grommet Location
9.3. Connect the new harness to the BCA in the location shown in Fig. 8. For details on the connection, see
Fig. 9.

Fig. 8, BCA Harness Connection Location

Daimler Trucks
North America LLC

Customer Advisory Letter
CAL FTL 54-021

December 6, 2021

Fig. 9, BCA Harness Connection Details
9.4.

Temporarily remove the connector, shown in Fig. 10, from the battery load disconnect switch end of the
new harness. Use tool DK10CHA17002-2 or a similar tool to remove the terminals from the connector,
shown in Fig. 11. Make note of the cavity position of each wire removed for installation later.

Fig. 10, Remove the Battery Load Disconnect Switch Connector

Fig. 11, Battery Load Disconnect Switch Connector Details

Daimler Trucks
North America LLC

Customer Advisory Letter

December 6, 2021
CAL FTL 54-021
9.5.
Locate the grommet passing through the firewall on the driver’s side and remove the cable tie from the
grommet on the engine side of the firewall as shown in Fig. 12.
NOTE: There may be a large section of tape on the cab side of the harness that will need to be removed in
order to pass the new harness through.

Fig. 12, Cable Tie on the Engine Side of the Pass-Through Grommet
9.6. Insert a large cable tie through the grommet from the engine side of the firewall into the cab. The cable
tie will be used to pull the harness through the firewall.
NOTE: Lubricate the end of the cable tie with WD-40 or a similar lubricant to help it pass through

the grommet. If the cable tie will not pass through, lubricate a screwdriver to help with the
insertion of the cable tie as shown in Fig. 13. Be careful not to chaff or damage the wiring.

Fig. 13. Screwdriver Inserted Through Grommet

Daimler Trucks
North America LLC

Customer Advisory Letter
CAL FTL 54-021

December 6, 2021
9.7.

Tape the end of the harness to the cable tie under the dash as shown in Fig. 14.

Fig. 14, End of Harness Taped to Cable Tie Inserted Through Grommet
9.8.

Apply a small amount of WD-40 or similar lubricant to the tape, then from the engine side, pull the cable
tie to pull the end of the harness through the grommet as shown in Fig. 15.

Fig. 15, Pulling the Harness through the Grommet

Daimler Trucks
North America LLC

Customer Advisory Letter

December 6, 2021
CAL FTL 54-021
9.9.
After pulling the harness through the firewall grommet, install the connector removed from the battery
load disconnect switch end of the new harness in step 9.4.
Make sure each wire is installed in the correct cavity position. See Fig. 11.
9.10. If equipped, remove the detachable side fairing on the driver’s side for under the cab access for harness
routing.
9.11. Route the harness from the firewall grommet down the driver’s side front wall as shown in Fig. 16, and
then under the cab as shown in Fig. 17, to the new battery cutoff switch location on a bracket at the back
of the cab. Secure the new harness with cable ties to the existing harnesses or airlines as needed.
NOTE: Refer to installation drawing D66-05723-000 for routing and clipping details.

Fig. 16, Harness Routing from the Grommet Down Driver’s Front Wall

Fig. 17, Harness Routing Under the Cab to the Battery Load Disconnect Switch

Daimler Trucks
North America LLC

Customer Advisory Letter

December 6, 2021
CAL FTL 54-021
NOTE: If a tractor protection valve is present, use the existing fastening hardware to install the switch bracket.
10. Install the switch bracket on the back of cab as shown in Fig. 19 using the two hex screws and nuts.

Fig. 19, Bracket and Battery Switch Location at Back of Cab
11. Install the battery cutoff switch on the bracket as shown in Fig. 20 using four screws.

Fig. 20, Battery Cutoff Switch Installed on Bracket

Daimler Trucks
North America LLC

Customer Advisory Letter

December 6, 2021
12. Connect the harness to the backside of the switch as shown in Fig. 21.

CAL FTL 54-021

Fig. 21, Harness Connected to Battery Cutoff Switch
13. Install the warning label (part number 24-01618-002) on the door jamb as shown in Fig. 22.

Fig. 22, Battery Load Disconnect Switch Label Installation
13. Install the warning label (part number 24-01594-000), shown in Fig. 23, on the outside centerline of the frame
rail, in line with the starter power leads.
Note: Starters can be located on the right or left depending on the engine installed. The figure below
depicts the starter on the left side of the vehicle.

Customer Advisory Letter

Daimler Trucks
North America LLC

CAL FTL 54-021

December 6, 2021

Fig. 23, Warning Label Installation

14. Install all dash panels previously removed.
15. Reconnect the battery negative cable.
16. If removed, install the detachable side fairing.
17. Verify that the battery cutoff switch operates correctly.