Usage:
768C (02X),
772B (64W),
776C (2TK),
784B (5RK) Tractors;
769C (01X),
773B (63W),
777C (4XJ),
785B (6HK),
789B (7EK),
793B (1HL) Trucks;
771C (3BJ),
775B (7XJ) Quarry Trucks
Description of Change: A relay has been added to the stop lamp circuit. The relay is used with the 2M-9346 Pressure Switch to improve the service life of the pressure switch.
Adaptable To: The new 3E-5239 Relay Assembly is effective with 768C (02X404), 772B (64W303), 776C (2TK91), 784B (5RK19) Tractors, 769C (01X7008), 773B (63W4570), 777C (4XJ815), 785B (6HK519), 789B (7EK383), 793B (1HL397) Trucks; 771C (3BJ263) and 775B (7XJ299) Quarry Trucks. The relay can be added to earlier machines using the following parts and procedure.
(1) Existing cab ground boss. (2) 3E-5239 Relay Assembly. (3) 2M-9346 Pressure Switch. (A) Added wire. (B) Original wiring harness.
Relay Installation Procedure
1. Remove the original 2M-9346 Pressure Switch (stop lamp switch) and install a new 2M-9346 Pressure Switch.
2. Weld the 8W-9022 Plate in a vertical position to rear wall of the cab. The plated should be mounted close to the brake pressure switch.
3. Mount the 3E-5239 Relay Assembly on the 8W-9022 Plate using the 8T-0328 Washer and 8T-1688 Screw. The relay should be mounted vertically with the terminals pointing down.
4. Cut off the terminals on the 103-YL and d604-OR wires at the wiring harness that is connected to the 2M-9346 Pressure Switch. Using a 092-8226 Splice, connect two appropriate lengths of 5P-5623 Wire to the 103-YL wire. Protect this splice with a length of 6V-2689 Tubing. Heat the tubing to seal the splice.
5. Insert each of the 103-YL wires into positions 4 and 5 of the 9X-1054 Plug and pull the wires through the plug. Install a 9X-1056 Terminal on each wire. Then, pull the wires back into the connector to lock them in place.
6. Using a 092-8226 Splice, connect an appropriate length of 5P-5623 Wire to the 604-OR wire. Protect this splice with a length of 6V-2689 Tubing. Heat the tubing to seal the splice. Pull this wire through the 9X-1054 Plug in position 1 and install a 9X-1056 Terminal. Lock the terminal in place.
7. Crimp a 2L-8076 Terminal onto an appropriate length of 5P-5623 Wire. Connect this to one stud on the 2M-9346 Pressure Switch. Crimp a 2L-8069 Terminal on the other end of this wire and fasten this to the existing cab ground boss.
8. Crimp a 2L-8076 Terminal onto an appropriate length of 5P-5623 Wire and connect this to the other stud of the 2M-9346 Pressure switch. Pull the other end of this wire through the 9X-1054 Plug in position 2. Install a 9X-1056 Terminal and lock it in place.
9. Plug the 9X-1054 Plug into the 3E-5239 Relay.
10. Test the stop lamps for correct operation.