SFN-20231107A_Replace the ignition solenoid with an ignition relay

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TICO Document #: SFN-20231107A (formerly TES 277)

Description of Procedure: This field upgrade is to replace the ignition solenoid with an ignition relay on Diesel and CNG TICO tractors

Units Affected: All diesel and CNG TICO tractors

Parts Required: KIT –DIESEL/CNGPDC, SOLENOID TO RELAY REPLACEMENT 970113 (QTY) 1

Planned Labor: 45 Minutes

Instructions:

  1. Park the vehicle on a flat surface, apply the parking brake and chock wheels. If your company utilizes a “Lock Out, Tag Out” policy, you should employ it during this procedure.

  1. Remove the battery box cover and disconnect the black ground battery cables (Figure 1).

  2. Remove the batteries or insulate terminal ends with a non-conductive wrap to prevent inadvertent contact between battery terminals and cables.

  1. Locate the PDC box underneath the cab step grate (Figure 2). 

  1. Remove (4) bolts, nuts and (8) washers on the cab step grate with a 9/16” socket wrench and 9/16” wrench. The wrench is used to hold the nuts below the grate in place. Retain hardware (Figure 3.)

  1. Remove (8) bolts and washers on the chassis PDC box (Figure 4a) and remove the lid (Figure 4b). Retain the hardware.

  1. Remove (2) 5/16-18 nuts and (2) #10-32 nuts from ignition solenoid studs (Figure 5a). 

  2. Remove all ring terminals from solenoid studs (Figure 5b). Discard the hardware.

  1. Remove both busbars from the solenoid (Figure 6). Do not discard the (2) 3/8” nuts or the busbar on the left; they will be reused. You may discard the busbar on the right. 

  1. Remove the (2) bolts used to mount the solenoid to PDC box (Figure 7a).

  2. Remove and discard the solenoid from the PDC box (Figure 7b).

  1. Install the red junction block and black junction block onto the junction block bracket using (4) #10-32 UNF X 3/4” long bolts, (4) #10-32 washers, and (4) #10-32 nylon lock nuts (Figure 8). 

    The red junction block goes on the left side of the junction block bracket and the black junction block goes on the right. 

  1. Place the bracket assembly onto the hole pattern where the ignition solenoid used to be mounted. 

  2. Install the junction block bracket with (1) 1/4-20 X 3/4” long bolt, (2) 1/4 washers, and (1) 1/4-20 nylon lock nut on the bottom mounting hole (Figure 9). 

Install the relay harness P/N: 621606 (Figure 10)

  1. Insert (1) #10-32 UNF X 3/4” long screw, (2) #10-32 washers, (1) 1/4 washer, and (1) #10-32 nylon lock nut on the top hole of bracket (Figure 11).

    Note: Insert #10-32 bolt by first placing (1) #10-32 washer onto bolt, then placing the 1/4 washer onto bolt. This allows #10-32 bolt to fit in 1/4” mounting hole. 

  1. Orient the relay harness so that it is pointing toward the center of the PDC box (Figure 12).

  1. Locate the (2) white 16-gauge ground wires that were removed from the solenoid, along with the white ground wire from the relay harness and install them onto the black junction block (Figure 13a).

  2. Make sure the wires are oriented vertically as shown in Figure 13b.

    Note: The PDCbox on CNG trucks will only have (1) white 16-gauge wire that was removed from the solenoid.

  1. Locate the (2) yellow 16-gauge ignition wires that were removed from the solenoid, along with the yellow key switch ignition wire from the relay harness and install them onto the red junction block with a vertical orientation as shown in Figure 14.

    Note: The PDC box on CNG trucks will only have (1) yellow 16-gauge wire that was removed from the solenoid.

  1. Install the relay harness battery cable (Figure 15a) on the circuit breaker stud where right side busbar used to be located (Figure 15b).

    Use previous busbar hardware (3/8 -16” nut) to install.

  1. Notice the battery cable routing for placement (Figure 16).

  1. Re-install the left side busbar and tilt it away from the junction block bracket about 30 degrees to the left so it will not touch the bracket or the PDC box (Figure 17).

  1. Insert (1) 5/16-18 X 1” bolt into the busbar (Figure 18).

  1. Locate the yellow 12-gauge ignition wire that was removed from the solenoid along with the red 8-gauge ignition power cable from the relay harness and insert the terminals onto the 5/16-18 X 1” bolt (Figure 19).

  1. Ensure that no ground wires (white) are in contact with any power wires (red and yellow).

Note: Do not zip tie ground wires (white) and power wires (red and yellow) together. 

  1. Zip-tie all loose wires so that they are secure (Figure 20).

  1. Remove “IGNITION SOLENOID decal and replace it with “IGNITION RELAY” decal as shown in figures 21a and 21b.

  1. Apply a new schematic decal inside of PDC box where the previous schematic decal was located. 

  • 34A Diesel truck decal P/N: 500471 (Figure 21a)

  • 34B CNG truck decal P/N: 500472 (Figure 21b)

  1. Re-install (8) bolts and washersback onto the chassis PDC cover using a 7/16” socket wrench (Figure 22).

  1. Re-install (4) bolts, nuts and (8) washers for the chassis PDC grate using a 9/16” socket wrench and 9/16” wrench to hold the nuts in place below the grate (Figure 23).

  1. Reconnect the battery and test start-up to ensure proper function. 

  1. Once tested, return vehicle to service (Figure 24)