Mercury 305 CID - Oil Pressure Switch; Testing; Water Temperature Switch; Removal

4D-12 - INSTRUMENTATION 90-823225--1 1096
c. If horn sounds, problem is in tan/blue wire
back to engine or switches on engine.
+
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b
c
d
a
e
f
g
–
Buzzer For 1994 Model And Older Carbureted En-
gines
a - Jumper Wire To 12 Volt (+) Step 3
b - Jumper Wire To Negative (–) Step 3
c - Jumper Wire To 12 Volt (+) Step 4
d - Jumper Wire To Negative (–) Step 4
e - PURPLE Wire
f - RED Wire
g - TAN/BLUE Wire
74046
Buzzer For EFI and 1995 Model And Newer Car-
bureted and EFI Engines (No Timer Circuit)
Oil Pressure Switch
TESTING
1. Remove wire from sender terminal.
2. Connect continuity meter between sender termi-
nal and sender hex. (Sender shown removed for
clarity.)
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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 in-
dicate NO continuity.
Water Temperature Switch
REMOVAL
1. Drain coolant from closed cooling system into a
suitable container as outlined in Section 6B.
2. Remove tan/blue wire from temperature switch.
72613
b
a
a - TAN/BLUE Wire
b - Water Temperature Switch