
02May2020 |
Priority | PRODUCT IMPROVEMENT PROGRAM FOR REWORKING THE HORN CAB WIRING ON CERTAIN 794 AC, 796 AC, AND 798 AC OFF-HIGHWAY TRUCKS |
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7755 1408 7402 4493 | PI33166 |
NOTE: | AVSpare’s obligations under this Service Letter are subject to, and shall not apply in contravention of, the laws, rules, regulations, directives, ordinances, orders, or statutes of the United States, or of any other applicable jurisdiction, without recourse or liability with respect to AVSpare. |
NOTE: | This Program must be administered as soon as possible. When reporting the repair, use "PI33166" as the Part Number and "7751" as the Group Number, "56" as the Warranty Claim Description Code and "T" as the SIMS Description code. Exception: If the repair is done after failure, use "PI33166" as the Part Number, "7751" as the Group Number, "96" as the Warranty Claim Description Code, and "Z" as the SIMS Description Code. |
NOTE: | The information supplied in this service letter may not be valid after the termination date of this program. Do not perform the work outlined in this Service Letter after the termination date without first contacting your AVSpare product analyst. |
COMPLETION DATE |
TERMINATION DATE |
30Nov2020 | 31May2021 |
PROBLEM
The horn cab wiring needs to be reworked on certain 794 AC, 796 AC, and 798 AC Off-Highway Trucks. The existing horn activation button on the steering column may not be able to withstand a short-circuited horn and the wiring can fail. |
AFFECTED PRODUCT
Model | Identification Number |
794 AC | HRT00100-00106 MN500052-00056 MT500100-00152 |
796 AC | HRZ00500-00507 |
798 AC | ST700400 |
PARTS NEEDED
Qty |
Part Number | Description |
3 | 2L8076 | TERMINAL |
10 | 3S2093 | STRAP-CABLE |
33 | 6A3626 | WIRE-BULK (DECIMETERS) |
8 | 6V0491 | TERMINAL-BLADE |
10 | 7K1181 | STRAP-CABLE |
2 | 7T6365 | HOUSING-RECP |
1 | 1028802 | KIT-RCPT CONN |
20 | 1193662 | TUBE-BULK (CENTIMETERS) |
2 | 1261767 | PIN-CONNECTOR |
2 | 1261768 | SOCKET-CONNECTOR |
3 | 1364876 | SPLICE-WIRE |
1 | 1552270 | KIT-PLUG CONN |
2 | 3636530 | RELAY AS |
In order to allow equitable parts availability to all participating dealers, please limit your initial parts order to not exceed 44% of dealership population. This is an initial order recommendation only, and the ultimate responsibility for ordering the total number of parts needed to satisfy the program lies with the dealer. |
ACTION REQUIRED
Refer to the attached Rework Procedure. |
OWNER NOTIFIAVSION
Owners in the following countries will receive the attached Owner Notification: US Canada |
SERVICE CLAIM ALLOWANCES
NOTE: This is a 3.0-hour job | |||||
PARTS DISPOSITION
Handle the parts in accordance with your Warranty Bulletin on warranty parts handling. |
MAKE EVERY EFFORT TO COMPLETE THIS PROGRAM AS SOON AS POSSIBLE. |
EXAMPLE COPY OF OWNER NOTIFIAVSION XYZ Corporation 3240 Arrow Drive Anywhere, YZ 99999 PRIORITY - PRODUCT IMPROVEMENT PROGRAM FOR REWORKING THE HORN CAB WIRING ON CERTAIN 794 AC, 796 AC AND 798 AC OFF-HIGHWAY TRUCKS MODELS INVOLVED - 794 AC, 796 AC, and 798 AC Off-Highway Trucks Dear Cat Product Owner: The horn cab wiring needs to be reworked on the products listed below. The existing horn activation button on the steering column may not be able to withstand a short-circuited horn and the wiring can fail. You will not be charged for the service performed. Contact your local Cat dealer immediately to schedule this service. The dealer will advise you of the time required to complete this service. If you are no longer the owner of this product(s), please contact your local Cat dealer so that our records can be updated. Please refer the dealer to their Service Letter dated 02May2020 when scheduling this service. We regret the inconvenience this may cause you, and urge you to have this service performed as soon as possible to prevent unscheduled downtime. AVSpare Inc. Identification #(s) Attached to 02May2020 Service Letter |

1. Fabricate overlay harness assembly. Reference Image 1.1.1. |
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Image1.1.1 |
2. Fabricate three 117 circuit wires. Cut three wire lengths from 6A-3626 Bulk Wire (1). Cut one piece to a length of 518 millimeters (20.39 inch), one piece to a length of 196 millimeters (7.72 inch) and one piece to a length of 197 millimeters (7.76 inch). |
3. On one end of 518 millimeters (20.39 inch) wire, install 2L-8076 Ring Terminal As (2). On the other end slide a 65 millimeter (2.56 inch) piece of 119-3662 Heat Shrink Tube (3) over end of the wire. Install 136-4876 Splice (4) on end of wire. Label wire ?117-HA1-YL?. |
4. Install one end of 196 millimeters (7.72 inch) wire and one end of 197 millimeters (7.76 inch) wire into the other end of 136-4876 Splice (4) in Step 3. Install 119-3662 Heat Shrink Tube (3) over splice. |
5. On other end of 196 millimeters (7.72 inch) wire and 197 millimeters (7.76 inch) wire, install 6V-0491 Blade Terminal (5). Label 196 millimeters (7.72 inch) wire ?117-HA2-YL? and 197 millimeters (7.76 inch) wire ?117-HA3-YL?. |
6. Install blade terminal end of each wire to Position 86 on each 7T-6365 Receptacle Housing (6). |
7. Fabricate three 200 circuit wires. Cut three wire lengths from 6A-3626 Bulk Wire (1). Cut one piece to a length of 333 millimeters (13.11 inch), one piece to a length of 129 millimeters (5.08 inch) and one piece to a length of 131 millimeters (5.16 inch). |
8. On one end of 333 millimeters (13.11 inch) wire, install 2L-8076 Ring Terminal As (2). On the other end slide a 65 millimeter (2.56 inch) piece of 119-3662 Heat Shrink Tube (3) over end of the wire. Install 136-4876 Splice (4) on end of wire. Label wire ?200-HA9-BK?. |
9. Install one end of 129 millimeters (5.08 inch) wire and one end of 131 millimeters (5.16 inch) wire into the other end of 136-4876 Splice (4) in Step 8. Install 119-3662 Heat Shrink Tube (3) over splice. |
10. On other end of 129 millimeters (5.08 inch) wire and 131 millimeters (5.16 inch) wire, install 6V-0491 Blade Terminal (5). Label 129 millimeters (5.08 inch) wire ?200-HA7-BK? and 131 millimeters (5.16 inch) wire ?200-HA8-BK?. |
11. Install blade terminal end of each wire to Position 87 on each 7T-6365 Receptacle Housing (6). The 129 millimeters (5.08 inch) wire labeled ?200-HA7-BK? must be installed to the same 7T-6365 Receptacle Housing (6) that the 196 millimeters (7.72 inch) wire labeled ?117-HA2-YL? is installed. The 131 millimeters (5.16 inch) wire labeled ?200-HA8-BK? must be installed to the same 7T-6365 Receptacle Housing (6) that the 197 millimeters (7.76 inch) wire labeled ?117-HA3-YL? is installed. |
12. Fabricate five 322 circuit wires. Cut five wire lengths from 6A-3626 Bulk Wire (1). Cut one piece to a length of 575 millimeters (22.64 inch), one piece to a length of 124 millimeters (4.88 inch), one piece to a length of 125 millimeters (4.92 inch), one piece to a length of 387 millimeters (15.24 inch) and one piece to a length of 400 millimeters (15.75 inch). |
13. On one end of 575 millimeters (22.64 inch) wire, install 2L-8076 Ring Terminal As (2). On the other end slide a 65 millimeter (2.56 inch) piece of 119-3662 Heat Shrink Tube (3) over end of the wire. Install 136-4876 Splice (4) on end of wire. Label wire ?322-HA4-GY?. |
14. Install one end of 124 millimeters (4.88 inch) wire and one end of 125 millimeters (4.92 inch) wire into the other end of 136-4876 Splice (4) in Step 13. Install 119-3662 Heat Shrink Tube (3) over splice. |
15. On other end of 124 millimeters (4.88 inch) wire and 125 millimeters (4.92 inch) wire, install 6V-0491 Blade Terminal (5). Label 124 millimeters (4.88 inch) wire ?322-HA5-GY? and 125 millimeters (4.92 inch) wire ?322-HA6-GY?. |
16. Install blade terminal end of each wire to Position 85 on each 7T-6365 Receptacle Housing (6). The 124 millimeters (4.88 inch) wire labeled ?322-HA5-GY? must be installed to the same 7T-6365 Receptacle Housing (6) that the 196 millimeters (7.72 inch) wire labeled ?117-HA2-YL? and 129 millimeters (5.08 inch) wire labeled ?200-HA7-BK? is installed. The 125 millimeters (4.92 inch) wire labeled ?322-HA6-GY? must be installed to the same 7T-6365 Receptacle Housing (6) that the 197 millimeters (7.76 inch) wire labeled ?117-HA3-YL? and 131 millimeters (5.16 inch) wire labeled ?200-HA8-BK? is installed. |
17. On one end of 387 millimeters (15.24 inch) wire and 400 millimeters (15.75 inch) wire, install 126-1767 Pin (7). |
18. On the other end of 387 millimeters (15.24 inch) wire and 400 millimeters (15.75 inch) wire, install 6V-0491 Blade Terminal (5). Label 387 millimeters (15.24 inch) wire ?322-HA10-GY? and 400 millimeters (15.75 inch) wire ?322-HA11-GY?. |
19. Install blade terminal end of each wire to Position 30 on each 7T-6365 Receptacle Housing (6). The 400 millimeters (15.75 inch) wire labeled ?322-HA11-GY? must be installed to the same 7T-6365 Receptacle Housing (6) that the 196 millimeters (7.72 inch) wire labeled ?117-HA2-YL?, 129 millimeters (5.08 inch) wire labeled ?200-HA7-BK? and 124 millimeters (4.88 inch) wire labeled ?322-HA5-GY? is installed. The 387 millimeters (15.24 inch) wire labeled ?322-HA10-GY? must be installed to the same 7T-6365 Receptacle Housing (6) that the 197 millimeters (7.76 inch) wire labeled ?117-HA3-YL? and 131 millimeters (5.16 inch) wire labeled ?200-HA8-BK? and 125 millimeters (4.92 inch) wire labeled ?322-HA6-GY? is installed. |
20. Use electrical tape as required to bundle wires together to shape the fabricated harness assembly. |
21. Remove cab panel to install fabricated overlay harness in front of cab. |
22. Connect ?HORN 1 RELAY? (117-HA2-YL, 200-HA7-BK, 322-HA5-GY, 322-HA11-GY wires) housing to relay bank in the front of the cab as shown in Images 1.22.1 and 1.22.2. Connect ?HORN 2 RELAY? (117-HA3-YL, 200-HA8-BK, 322-HA6-GY, 322-HA10-GY wires) housing to relay bank in the front of the cab as shown in Images 1.22.1 and 1.22.2. Install 363-6350 Relay As to ?HORN 1 RELAY? housing and ?HORN 2 RELAY? housing. Note: Image 1.22.2 shows the relay assembly locations for a quick disconnect cab. The quick disconnect cab was effective in production with trucks MT5142-UP, HRT101-UP, HRZ502-UP, ST31-UP and ST7400-UP. For trucks MN51-UP, MT51-141, HRT1-100 and HRZ1-501 the relay assemblies can be located in any of the open positions in the relay bank. |
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Image1.22.1 |
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Image1.22.2 |
23. Connect wire labeled ?117-HA1-YL? to Terminal Block TB10, Position A. Connect wire labeled ?322-HA4-GY? to Terminal Block 10, Position B. See Images 1.22.1 and 1.23.1. |
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Image1.23.1 |
NOTE: Step 24 is required for trucks MN51-UP, MT51-141, HRT1-100 and HRZ1-501 only. 24. Remove 11D2 and 11D3 black wires from Terminal Block TB10 Position B. Cut the ring terminal ends off of wires and install 126-1768 Sockets. Insert wires into 102-8802 Receptacle Kit. Insert 11D2 wire into Position 1 and 11D3 wire into Position 2. Insert pin ends of wires labeled ?322-HA10-GY? and ?322-HA11-GY? into 155-2270 Plug Kit. Insert 322-HA10-GY wire into Position 1 and 322-HA11-GY wire into Position 2. Connect receptacle kit to plug kit. Note: For trucks MN51-UP and MT51-118 the removed wires from Terminal Block TB10, Position B are 11D2-C3-BK and 11D3-C16-BK part of 442-3759 Platform Harness As. Note: For trucks MT5119-141, HRT1-100 and HRZ1-501 the removed wires from Terminal Block TB10, Position B are 322-N3-GY and 322-N17-GY part of 442-3759 Platform Harness As. |
25. Connect wire labeled ?200-HA9-BK? to Cab Ground 17 on left side of cab as shown in Images 1.22.1 and 1.25.1. |
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Image1.25.1 |
NOTE: Step 26 is required for trucks MT5142-UP, HRT101-UP, HRZ502-UP, ST31-UP and ST7400-UP only. 26. Remove existing wire in Position B and insert wire labeled ?322-HA11-GY? into Position B on connector. Remove existing wire in Position D and insert wire labeled ?322-HA10-GY? into Position D on connector. See Images 1.22.1 and 1.26.1. Note: The removed wires are 322-HM16-GY (Position B) and 322-HM8-GY (Position D) in Connector HM-C9 part of 557-6273 Harness As. |
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Image1.26.1 |
27. Secure fabricated overlay harness assembly to cab harness as required using 7K-1181 Straps and or 3S-2093 Straps as required. |
28. Re-install cab panel that was removed in Step 21. Tighten screws to 12 Nm (9 lb ft). |