Oil Pressure Switch; Transmission Fluid Temperature Switch - Mercury MerCruiser MCM 454 Mag MPI Service Manual

INSTRUMENTATION

Oil Pressure Switch

TESTING
1. Remove wire from sender terminal.
2. Connect continuity meter between sender terminal and sender hex. (Sender shown
removed for clarity.)
3. With engine not running, meter should indicate full continuity.
4. Start engine. With engine running and engine oil pressure above 6 psi (41 kPa), meter
should indicate no continuity.

Transmission Fluid Temperature Switch

Switch is located on transmission. Switch is normally open. This switch is used on MIE
engines, if equipped.
Opens
Closes
REMOVAL
1. Disconnect harness wires at switch.
2. Remove switch and sealing washer.
Typical Location
Index
Page 4D-18
Downloaded from https://needmanual.com/
a - Transmission Fluid Temperature Switch With Sealing Washer
b - Harness Wires
87-88031 Switch
180-200 F (82-93 C)
220-240 F (104-116 C)
b
a
SERVICE MANUAL NUMBER 23
72764
72845
90-861326--1 MARCH 1999