Chrysler RAM TRUCK 2500 1994 Service Manual page 439

8F - 10 AUDIO SYSTEMS
ANTENNA
ANTENNA DIAGNOSIS
Turn Ign. Key to
ACC.
Tune to Known
Strong AM Station
Check Antenna
Connections
No
Oieck for
Reception Using
A Test Antenna
Repair as
Required*
Yes
*Be Sure Antenna is
Properly Grounded to Car.
(Poor Grounding of Antenna
May Cause Engine Noise or
Static Especially on AM)
Remove Radio
For Service
Replace or Repair
Defective Antenna
Or Lead in
J 9 2 8 M
T E S T I N G
Antenna performance may be tested by substitut­
ing a known good antenna. Check short or open cir­
cuits with an ohmmeter or test lamp, once the
antenna cable is disconnected from the radio, as fol­
lows:
(1) Continuity should be observed between the tip
of the mast and radio end pin (Fig. 1).
(2) No continuity or a very high resistance of sev­
eral megaohms should be observed between the
ground shell of the connector and radio end pin.
(3) Continuity should be observed between the
ground shell of the connector and the mounting hard­
ware on the fender.
TIP OF MAST
TEST POINT
RY684
Fig. 1 Antenna Test Points
BENCH T E S T F O R ANTENNA MALFUNCTION
(1) With test lamp and battery i n circuit;
(a) attach one test lead to concentric pin on
lead-in connector
(b) other test lead to tip of mast (Fig. 2).
The lamp should light indicating continuity.
PR519
Fig. 2 Antenna Bench Test Points
(2) Keeping one lead on connector pin, clip other
lead on antenna body assembly. The lamp should
NOT light. I f i t does, look for a short circuit i n the
body or i n the cable, probably at the connector.
(3) Remove clip lead from connector pin and clip on
outer shell of connector. Connect other clip lead to
antenna body assembly. The lamp should light again.
I f i t does not light, antenna shielding has an open
circuit.
Wiggle cable over its entire length to reveal
intermittent short or open circuits during steps
1,
2 and 3.