Piper CHEROKEE WARRIOR PA-28-151 1995 Maintenance Manual page 359

PIPER CHEROKEE WARRIOR SERVICE MANUAL
10-75. TROUBLESHOOTING.
TABLE X-XVII. TROUBLESHOOTING CYLINDER HEAD TEMPERATURE GAUGE
TROUBLE
Instrument shows no indication.
Instrument goes all the way to
upper stop.
10-76. EXHAUST GAS TEMPERATURE GAUGE (Alcor)
10-77. GENERAL
This instrument, known as EGT, is used to aid the pilot in selecting an economical fuel-air mixture for
cruising flight at a power setting of 75 percent or less, and to adjust mixture setting at altitudes above 5,000
feet. It is a sensing device to monitor the temperature of exhuast gases leaving the engine cylinders. The
gauge is adjustable. If found defective after checking with troubleshooting chart, it must be replaced. If leads
to gauge are defective, they must be replaced. Because the resistance of the electrical leads is critical for proper
gauge operation, they must be replaced with the same type and length of wire, .
10-78. REMOVAL AND INSTALLATION OF EGT PROBE AND GAUGE
a. To remove EGT probe and gauge:
1. Disconnect wires from EGT gauge at instrument panel.
2. Remove four bolts holding gauge to instrument panel and remove gauge.
3. Remove wires from wire harness going to engine.
4. Loosen clamp holding EGT probe to number one cylinder exhaust manifold and remove
probe.
b. To install EGT probe and gauge (Refer to Figure 10-10):
1. Install probe into hole in number one cylinder exhaust manifold and secure with clamp.
2. Route thermocouple wires with existing wire harness to instrument panel.
3. Install EGT gauge into instrument panel and secure with four bolts.
4. Connect thermocouple wires to rear of EGT gauge.
10-79. CLEANING AND INSPECTION OF EGT
Do not connect ohmmeter across meter. It will burn out the
movement of the meter.
Unless mechanical damage is evident, broken glass, bent or broken pointer, or broken case, check as
follows (before removing instrument):
a. Remove probe from exhaust stack and check for broken weld (at tip end) or burnt off end.
Measured resistance of probe must be 0.8 ohms. Clean connections with steel wool before assembly.
Revised: February 28, 1995
CAUSE
Power supply wire.
Defective instrument.
Master (BAT) switch OFF.
Wire broken between sender and
gauge.
Defective sender.
—CAUTION—
2C23
Island Enterprises
REMEDY
Repair wire broken.
Replace instrument.
Select master (BAT) switch O N .
Repair wire.
Replace sender.
INSTRUMENTS