SB-10057808-3906

Service Bulletin 44
Wiper Harness Installation Guide
Tools Required
3/8 wrench or socket set
Philips Screwdriver or Drill with Philips bit
S2 Square Bit
Wire Strippers
Cutters for removing Zip Ties
Items Needed
The fix for the Bus includes installing:
5041867 HARNESS WIPER RELAY BUS 15
5044495 RELAY WIPER 40A WEATHERPROOF COVER
The fix for the Phaeton includes installing:
5042869 HARNESS WIPER RELAY PH 15
5044495 RELAY WIPER 40A WEATHERPROOF COVER
Before starting, confirm new harness installation is required!
Be sure to check to see if the new harness has already been installed. The new harness uses three
relays that are mounted on the firewall near the wiper motor. If there are already three relays
present, then there is no need to install the new harness.

1. Unplug Wiper Motor
To begin installing the new harness the old harness must be removed. First, unhook the
harness from the wiper motor by unplugging it. Push up on the small black lever as
shown in the picture below. Then pull downward on the white connector shown below to
unplug.

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Service Bulletin 44
Wiper Harness Installation Guide
2. Remove Relays
Remove the red relay power wires from the circuit breakers by removing the 3/8” nuts.
Keep these nuts because they will be used later to install the new harness.
Remove both relays from the relay board by removing the mounting screws. Keep these
screws because they will be used later when installing the new harness.

3. Continue Uninstalling the Wiper Harness
Continue uninstalling the wiper harness by removing mounting clips and zip ties as
necessary.

4. Unplug Wiper Interface Connector
The harness is attached to the connector shown in the picture below. Disconnect the
harness by pulling the connectors apart.

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Service Bulletin 44
Wiper Harness Installation Guide
5. Remove Ground Wires from Ground Bar
The wiper harness ground wires are connected to a small ground bar mounted to the
firewall. Remove these ground wires by loosening the screws that connect them. Take
care not to disturb any other ground wires that are connected to the ground bar. Also, be
careful when unscrewing the ground screws as they may become stripped if too much
force is applied.

6. Unplug Wiper Washer Bottle (If Present)
*The harness will include the wiper washer bottle connection on Phaeton models. Unplug
the connector at the wiper washer bottle. Take care when disconnecting so that the wires
do not get pulled out of the plug.

7. Transfer Relays to New Harness
After removing the old wiper harness, disconnect the two relays from the harness and
install them onto the new harness. Connect the third relay that shipped with the new
harness to the remaining connector.

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Service Bulletin 44
Wiper Harness Installation Guide
8. Mount Relays to Board and Firewall
Mount the two relays with the red wire and ring terminal to the relay board in the same
location from where they were removed:
- The relay with the blue wires is to be mounted next to the circuit breaker
labeled “HI WIPER 35 AMP”.
- The relay with the green wires is to be mounted next to the circuit breaker
labeled “LO WIPER 25 AMP”.
Reattach the red power wires to terminals. Place the ring terminals of the red wires onto
the circuit breaker terminals and tighten the 3/8” nuts that were previously removed.
Attach the third relay to the firewall near the relay board using a self-tapping screw.
Refer to step 2 which covered removing the relays.

9. Reconnect Wiper Motor
Connect the new harness and wiper motor together. Be sure to push firmly together until
the small black lever clicks into place.
Refer to step 1 which covered unplugging the connection.

10. Reconnect Wiper Interface
Connect the new harness and the wiper interface together. Be sure to push firmly
together so the connection is secure.
Refer to step 4 which covered unplugging the connection.

11. Reconnect Ground Wires
Strip ground wires on new harness and install them into the ground bar. Be sure that
ground wires are securely fastened by screwing the ground screws tightly.
Refer to step 5 which covered removing the ground wires.

12. Reconnect Wiper Washer Bottle
Reconnect the wiper washer connector to the washer bottle by plugging the connecter
back in.
Refer to step 6 which covered unplugging the connection.

13. Secure Harness
Lastly, secure the harness using zip ties and mounting clips to ensure that there are no
loose wires dangling.

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Tiffin Motorhomes, Inc.
105 2nd Street NW
Red Bay, AL 35582
256-356-8661
SB-44
Opposing Wiper Harness Upgrade in 2015 Phaetons
And 2015 Allegro Buses
January 13, 2015
Dear Tiffin Customer,
Tiffin Motorhomes recently made an upgrade to the wiring harness that is installed on certain 2015
Phaetons and Allegro Buses. This change added a relay to the low speed on the wipers and created an
unexpected cycling relay issue to develop. Changes have been made to correct the cycling relay issues,
but on units that have already shipped we need to have an upgraded wiring harness installed.
Please take your coach to one of our dealers or a reputable service center of your choice to have this
harness installed. We have included the parts needed and the instructions for the new wiring harness to
be installed. We are allowing 45 minutes for this upgrade to be completed.
We regret any inconvenience this action may cause, but feel certain you understand our interest in
motor vehicle safety.
Thank you,
Tiffin Motorhomes, Inc.