Copyright 2019 Discovery Owner's Association, Inc.

Transmission Keypad Illumination

If your Discovery chassis was built between January 5 and September 11, 1998, your transmission keypad is not illuminated when you lights are on. Needless to say, this makes it very difficult to hit the right buttons! If your keypad is not illuminated at night when your lights are on, contact your nearest Freightliner Chassis Service Center and advise them of the problem. Freightliner has issued Service Bulletin CSU 54-08, which involves installation of a new cable to the keypad. (Note that you may have to advise your Freightliner dealer of this Service Bulletin).

Since Freightliner did not do a recall on this, many owners were not aware of this Freightliner Service Bulletin. Now, Freightliner is charging owners for this modification. Perhaps, if you complain nicely to someone at Gaffney, you can get them to do it for free, or maybe at least give you the new harness for free.

If you would like to attempt the modification yourself, here are the instructions:

Recreational Vehicle Custom Chassis, Service Bulletin 54-8

General Information
On some vehicles, the gear selector backlight may not operate correctly. This is due to the harness wiring configuration, which has been changed in Production and is now correctable in the field.

On XC chassis built with the Cummins ISB/C or Caterpillar engines and Allison MD3060 transmissions between January 5 and September 11,1998, the new WTEC III wiring for the Allison gear shift selector is connected to the cab through the same cab harness that the earlier WTEC II used. However, this cab harness prevents the gear selector backlight from operating.

Production corrected the problem after September 11, 1998, when a new cab harness was used.

Two jumper harnesses have been developed for the affected vehicles. Follow the instructions below to install the two jumper harnesses.

Harness Installation
1. Park the vehicle on a level surface. Shut down the engine. Set the parking brake and chock the rear tires.

2. Disconnect the batteries.

3. Unplug the 20-pin, round, gray connector that connects the transmission shifter harness to the cab harness. This connector is about 6 inches (150 mm) from the shifter lever.

4. Remove the lock wedge from the connector on the cab harness.

Use Packard pick tool #12094430 (wide pick) or #12122647 (56 series) to remove the wire terminals for the ground circuits E186 and E188 (black insulation) from cavities "T" and "V". of the cab harness connector. See Fig. 1. Remove the yellow wire for the dimmer circuit (E187) from cavity "U" of the cab harness connector.

5. Tape the three newly-removed wires out of the way or cut and apply heat-shrink tubing to the wire ends.

6. Install the female terminal on the yellow wire of the new dimmer input harness (06-29892-000) into the "U" cavity of the 20-pin cab connector.

7. Fasten the new dimmer harness to the existing cab harness with tie wraps every few inches until you reach the wire and connector exiting the cab harness from the dimmer control.

8. Connect the connector from the new dimmer harness (circuit 1052C) to the connector on the wire from the dimmer control.

9. Install the two female terminals on the black wires of the new backlight ground harness (06-29893-000) into cavities "T" and "V" of the 20-pin connector on the cab harness.

10. Connect the ring terminal at the other end of the backlight ground harness to a ground stud. Use tie wraps or tape to secure the ground harness along its route to the ground stud.

11. Install the lock wedge on the 20-pin connector and reconnect the shifter harness to the cab harness.

12. Connect the batteries. Test the operation of the shift selector backlight by turning on the lights and rotating the dimmer control knob.

13. Remove the chocks from the tires.

Parts Availability

The dimmer input harness (06-29892-000) and the backlight ground harness (06-29893-000) are available through the PDCs.


Normal warranty applies. When submitting claims, refer to this service bulletin by number in the story of the claim. Use the damage code and repair time information in Table 1.


The DISCOVERY OWNERS ASSOCIATION, INC, was formed to promote the sharing of information and the camaraderie of fellow Discovery motorhome owners. Membership in the club is limited to owners of Fleetwood Discovery motorhomes.


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