- Engines:
- 3606 (S/N: 8RB)
- 3608 (S/N: 6MC; 1ZD; 5PG; 8LL; 7WR)
- 3612 (S/N: 9RC)
- 3616 (S/N: 1PD)
The new 121-0597 Liquid Detector Gp replaces the former 7E-5508 Liquid Detector Gp in the above engines that are equipped with a continuous prelube system. The former liquid detector group is cancelled. The new liquid detector group includes a wiring harness that is removable.
Typically, both liquid detector groups are wired in series with a relay coil. The relay coil is part of an electrical circuit that indicates when the engine is prelubed. Usually, the former 7E-5508 Liquid Detector Gp was wired in order to switch positive 24 volts to the relay coil. However, the new 121-0597 Liquid Detector Gp must be wired in order to switch negative 24 volts to the relay coil. If a former 7E-5508 Liquid Detector Gp is replaced with a new 121-0597 Liquid Detector Gp, be sure that the new liquid detector group works. If the new liquid detector group does not work, ensure that the new liquid detector group is switching the negative 24 volts to the relay coil.
The following illustrations show typical examples of the correct wiring for the former 7E-5508 Liquid Detector Gp and the new 121-0597 Liquid Detector Gp. Connect the wiring as Illustration 2 shows.
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| Illustration 1 | g00903810 |
This illustration shows the typical wiring for a 7E-5508 Liquid Detector Gp . (X) 7E-5508 Liquid Detector Gp (Y) Relay Coil | |
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| Illustration 2 | g00903811 |
This illustration shows the wiring for a 121-0597 Liquid Detector Gp . (Y) Relay Coil (Z) 121-0597 Liquid Detector Gp | |