RING-RETAINING 1L4775 - Caterpillar

Engine:
3508B (S/N: S2B1-UP; S2D1-UP; S2E1-UP; S2F1-UP)
3512B (S/N: S2H1-UP; S2J1-UP; S2K1-UP; S2L1-UP; S2M1-UP; S2N1-UP)
3516B (S/N: S2R1-UP; S2S1-UP; S2W1-UP; S2X1-UP; S2Y1-UP)
The Marine Power Display (MPD) and the wiring harness used in the following instrument panel box groups can be rewired in order to increase the volume of the horn from 70 decibels to 84 decibels:
231-9900
231-9901
231-9902
231-9903Follow the steps in order to change the pin-outs on the wire harness and the wiring assembly:
Move wire 220-G81 from position 5 to position 12 on the 267-8623 Monitor Display Gp .
Remove wire 220-G101 from the 123-9694 Horn .
Move wire N756-G84 BK-18 from terminal A1 (positive terminal) to terminal A2 (negative terminal) on the horn.
Splice the M150-G286 wire. Connect a new wire from the splice to terminal A1 (positive terminal) of the horn.
Illustration 1 g01212694
Previous schematic
Illustration 2 g01212703
Updated schematicThe factory has changed the wiring diagrams on the engines that are currently produced in order to utilize the increased volume of the horn.This change is effective with the following panel harness assemblies:
237-9021 Panel Harness As change 05
240-8890 Panel Harness As change 04This change is effective with the following serial numbers in Table 1.
Table 1
Effective Serial Numbers    
S/N:S2B113-UP    
S/N:S2D105-UP    
S/N:S2E149-UP    
S/N:S2F104-UP    
S/N:S2H115-UP    
S/N:S2J125-UP    
S/N:S2K108-UP    
S/N:S2L162-UP    
S/N:S2M110-UP    
S/N:S2N107-UP    
S/N:S2R104-UP    
S/N:S2S120-UP    
S/N:S2W102-UP    
S/N:S2X142-UP    
S/N:S2Y104-UP