Exhaust Gas Temperature Gauge Troubleshooting - Piper Navajo Chieftain PA-31-350 Service Manual

NAVAJO CHIEFTAIN SERVICE MANUAL
NOTE
Local instrument shops can replace broken glass in the bezel and
check operation and calibration of the indicator. It is
recommended that the indicator be returned to Radair for
re-calibration.
d.
If trouble still exists after making the above checks, REMOVE the leads from the indicator and
using an ohmmeter check the extension cables and thermocouples for the following:
PROBE RESISTANCE:
1 ohm
EXT. LEAD RESISTANCE:
7 ohms
TOTAL RESISTANCE:
8 ohms
INDICATOR IMPEDANCE:
8 ohms
10-84. TROUBLESHOOTING.
TABLE X-XV. EXHAUST GAS TEMPERATURE GAUGE
Trouble
Cause
Remedy
Gauge inoperative.
Master Switch OFF.
Turn switch ON.
Circuit breaker OUT.
Defective gauge, probe
or wiring.
Adjusting potentio-
meter turned off scale.
Push breaker IN.
Check probe and lead
wires for chafing,
breaks or shorting
between wires and/or
metal structure.
Reset potentiometer.
Fluctuating reading.
Loose, frayed or broken
electrical leads or
faulty connections.
Clean and tighten
connections. Repair
or replace defective
leads.
10-85. REMOVAL AND REPLACEMENT. (Refer to paragraph 10-94 of this section.)
Reissued: 9/23/80
INSTRUMENTS
3C1