Gauge Replacement; Senders; Oil Pressure; Dual Station Sender Identification - Mercury 305 CID Service Manual

Gauge Replacement

Disconnect battery cables from battery.
1.
Remove wires from back of gauge.
2.
Remove hoses (vacuum, speedometer gauge).
3.
Disconnect light socket.
4.
Remove holding strap and remove gauge.
5.
Position gauge assembly in appropriate mount-
6.
ing hole.
Install holding strap and nuts. Tighten nuts evenly
7.
and securely.
IMPORTANT: Do not distort case or bracket by
over-tightening.
Connect ground (BLACK) wire to ground termi-
8.
nal, if gauge is not mounted in metal panel.
Connect other wires to gauge as shown in Sec-
9.
tion 4F.
Connect hoses (vacuum, speedometer gauges).
10.
Install gauge light socket.
11.
Coat all terminals with Quicksilver Liquid Neo-
12.
prene.
Reconnect battery cables to battery.
13.
Index
90-823225--1 1096

Senders

Oil Pressure

DUAL STATION SENDER IDENTIFICATION

Sender will have 353-AM stamped on hex of sender.

TESTING

IMPORTANT: Use following test procedure for
checking accuracy of oil pressure sender only. If
oil pressure gauge indicates zero oil pressure,
refer to Section 1C - "Troubleshooting."
Remove wire from sender terminal.
1.
Connect ohmmeter between sender terminal and
2.
sender case. Check ohms reading without en-
gine running (zero pressure), then check reading
with engine running. Compare oil pressure and
ohms readings as shown in following chart:
d
c
a
a - Positive Lead
b - Negative Lead
c - Wire Removed
d - Oil Pressure Sender
Oil
Ohms Reading
Pressure
Single
(PSI)
0 227-257
20 142-162.5
40 91.7-113.6
80 9-49
b
72754
Dual
113.5-128.5
71-81.25
45.8-56.8
4.5-24.5
INSTRUMENTATION - 4D-5