ALTERNATOR FUSE REPLACEMENT
Bulletin Type:

TSB

Bulletin #(s):

23-123

Job Code(s):

9803595

Flat Rate(s):

9803595 .40 HR Alternator Fuse
Inspection and Replacement

Incident:

Publication Date:

December 2023

Make(s):

Jayco - Entegra

Model(s):

Terrain (19Y)
Solstice LI (21BL)
Swift LI (20AL, 20DL, 20TL)
Launch (19Y)
Expanse LI (21BL)
Ethos LI (20AL, 20DL, 20TL)

Model Year(s):

2021-2024

Replace 300A MRBF Fuse with a 200A MRBF Fuse
2021-2024 Jayco Terrain, Solstice LI, Swift LI; 2021-2024 Entegra Coach Launch,
Expanse LI, Ethos LI with renogy 48V Lithium system

Affected Units:
Parts List:

1 FUSE,200A MRBF

Misc. Tools & Supplies:

Screwgun with Square Bit
Ratchet with 13MM Socket

The following symbols are the safety alert symbols. It is used to alert you to potential personal injury hazards. Obey
all safety messages that follow this symbol to avoid possible injury or death.

!

CAUTION

!

Indicates a potentially hazardous situation that, if not
avoided, may result in minor or moderate injury. It
may also be used to alert against unsafe practices.

!

WARNING

!

Indicates a potentially hazardous situation that, if not
avoided, may result in death or serious injury.

23-123_TSB Alternator Fuse Replacement

December 2023

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ALTERNATOR FUSE REPLACEMENT INSTRUCTIONS

WARNING

!



!

DO NOT touch any terminals or connectors unless all charging sources have been
disconnected.
Please make sure any battery charger or charge controller has been disconnected
before working on the battery.



CAUTION

!


!

DO NOT wear jewelry or other metal objects when working on or around the
battery.



1. Power down the lithium battery system.
A. Verify all charging sources have been disconnected:
i. Alternator
ii. Shore Power
iii. Rooftop Solar – disconnect near battery in the ‘OFF’ position
iv. Side Solar
B. Turn off the 12V Master Disconnect (Main Power) located near the rear of the sliding door.
C. Turn off the Inverter by pushing button on Inverter remote switch.
D. Press and release the Self-Locking Battery Switch. The button will be flush in the ‘OFF’ position.
E. Review the Samkoon Battery Screen to ensure that screen is off.

2. Remove components necessary to gain access to the fuse block. The removal procedure will be dependent
by floor plan.
A. Sprinter 19Y - Remove all screw retainer covers and fasteners from the lower ABS panel access
panel (Figure 1) to provide access to the battery equipment shelf (Figure 2).

Fig. 1

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Fig. 2

B. Promaster 20TL – With a screwgun and square bit, remove the bed lid assembly with bed
mechanism. (Figure 3)

Fig. 3
C. Promaster 20TL – With a screwgun and square bit, remove the bed lid assembly with bed
mechanism. (Figure 4)

Fig. 4
D. Ford Transit 21BL – remove the cushion
from the driver side and remove the jump
seat top plywood. (Figure 5)

23-123_TSB Alternator Fuse Replacement

Fig. 5

December 2023

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3. Replace the 300A Fuse with 200A Fuse (Figure 6)
A. Remove the fuse block cover.
B. Using a ratchet with 13mm socket, remove the
nut from alternator connection.
C. Remove 300A Fuse and replace with 200A Fuse.
D. Re-install the alternator cable connection and
secure with the nut previously removed.
Torque = 100 IN/LBS
E. Re-install the fuse block cover.

Fig. 6

4 . Power on the Lithium System
A. Verify all charging sources are disconnected:
i. Alternator
ii. Shore Power
iii. Rooftop Solar – disconnect near battery in the ‘OFF’ position
iv. Side Solar

B. Turning on the lithium battery: Turn battery on with the self-locking switch and self-resetting switch
i. Press and release the self-locking switch (typically installed behind an access panel near the
lithium battery)
ii. Next press and hold the self-resetting switch (typically installed overhead cabinet near
Firefly touchscreen) for approximately 5-10 seconds to turn on the battery. There will be a
series of clicks count to 5 after the last one.
C. Turn on Inverter by pushing button on Inverter remote switch. Green light will
turn on the remote switch when inverter is on. Turn off inverter when not
charging by shore power or using 120V outputs (outlets and Timberline Heater)
for short storage to preserve battery SOC%. Leaving the inverter ON when the
system is not in use can result in a 15-20% loss in SOC per day.
D. To turn on 12V power, press and release the momentary switch located near the
rear of the sliding door. Note that the red light by switch is illuminated when
the 12V power is active. To turn off the 12V power, press and release the
switch again and the red light by switch will turn off.
E. Verify Alternator charging source
i. The APS-500 indicator light should be flashing an Orange
light indicating it is synced with the battery BMS.
ii. Start the vehicle and verify that the Total Current
increases on the Samkoon screen.
1. Press and hold the gas pedal at approximately
1500RPM.

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2. Review the Samkoon screen Total Current. Dependent on the Total Voltage, the
Total Current can increase upwards to approximately 30-100A.

Total Current should increase from negative
current upwards to approximately 30-100A.

5. Re-install previously removed components to access the battery.

Jayco’s sole obligation under our limited warranty is to repair or replace defective materials and/or workmanship deemed our responsibility as determined
by Jayco in our sole discretion. Jayco reserves the right to use new and/or remanufactured parts or materials of similar quality to complete any work, and to
make parts and/or design changes as appropriate without notice to anyone. Jayco designs and/or materials changes are done without obligation to
incorporate such changes in previously manufactured product. Jayco makes every reasonable effort to ensure field remedies will not adversely affect
performance and/or safety of the unit. This field remedy is not intended to extend to future performance of this RV, or any of its materials, components or
parts beyond the standard warranty period. The RV owner’s obligation to notify Jayco, or one of its independent, authorized dealers, of a claimed defect
does not modify any obligation placed on the RV owner to contact Jayco directly when attempting to pursue remedies under state or federal law.
.

903 South Main Street • P.O. Box 460 • Middlebury, IN 46540

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