Dodge RAM TRUCK 1500 1995 Service Manual page 370

B R
OVERHEAD CONSOLE 8C - 3
essary to remove excessive residual magnetic
fields from the vehicle. See Compass Demagne­
tizing, in this group.
THERMOMETER DIAGNOSIS
The thermometer function is supported by a tem­
perature sensor, a w i r i n g circuit and a portion of the
overhead console display. The sensor is mounted to
the radiator support on t h e driver's side j u s t behind
the grille (Fig. 1).
A M B I E N T
T E M P E R A T U R E
S E N S O R
E L E C T R I C A L
C O N N E C T O R
J948C-18
Fig. 1 Temperature Sensor
I f any portion of the circuit fails, i t w i l l self-diag­
nose as an open or short circuit. The system w i l l dis­
play SC (short circuit) when the sensor is exposed to
temperatures i n excess of 60°C (140°F) or i f the cir­
cuit is shorted. I f the temperature is below -40°C
(-40°F) or an open circuit exists, the system w i l l dis­
play OC (open circuit).
To diagnose t h e temperature sensor, perform the
following procedures. I f t h e sensor and circuit are
OK, then the electronic module is faulty and should
be replaced.
SENSOR TEST
(1) T u r n t h e ignition switch to OFF. U n p l u g sensor
connector.
(2) Measure resistance of sensor. A t -40°F the re­
sistance is 336K ohms. A t 140°F the resistance is
2.488K ohms. Sensor resistance should read between
these t w o values. I f OK, go to Sensor Circuit Test. I f
not OK, replace the sensor.
SENSOR CIRCUIT TEST
(1) T u r n ignition switch to OFF. U n p l u g sensor
connector.
(2) Short the pins on t h e body h a l f of connector us­
i n g a j u m p e r wire.
(3) Remove the overhead console as described i n
Service Procedures.
(4) Check continuity between cavities 4 and 5 of
overhead console harness connector (Fig. 2). There
should be continuity. I f OK, go to next step. I f not
OK, repair open circuit as required.
GROUND
PANEL DIMMER
COURTESY
DOOR SWITCH
GROUND
HEADLAMPS ON/OFF
INPUT
Fig. 2 Overhead Console Harness Connector
(5) Remove jumper wire from temperature sensor
harness connector. Check continuity between cavities
4 and 5 of overhead console harness connector (Fig.
2) and a good ground. There should be no continuity.
I f OK, replace electronic module. I f not O K , repair
short circuit as required.