Pontiac Fiero 1988 Service Manual page 1032

HORNS
TROUBLESHOOTING HINTS
• Try the following checks before doing the Sys-
tem Diagnosis.
1. Check the BAT Fuse by operating the Cigar
Lighter.
2. Check that grounds are clean and tight.
3. If only one Horn sounds, check the DK GRN
(29) wire for an open between the Horns (see
schematic).
• Go to System Diagnosis for diagnostic tests.
SYSTEM DIAGNOSIS
• Diagnostic steps for the symptoms listed in
the following table are listed after the table.
SYMPTOM TABLE
A. Horns sound continuously
B. None of the Horns sound
A: HORNS SOUND CONTINUOUSLY
Connect:
T E S T LAMP
At: CONVENIENCE CENTER
Conditions:
© Horn Relay: REMOVED
• Horn Switch: OFF
Connect
Between
A(ORN)&B
(BLK)
Indication
Test Lamp
OFF
For Diagnosis
Seel
• If the test yields the correct response,
replace the Horn Relay.
1. Check BLK (28) wire and Horn Switch for
a short to ground (see schematic).
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COMPONENT LOCATION
Convenience Center Behind RH side of I/P
Fuse Block Behind LH side of I/P
Horn Brush Top of steering column
Horn Brush Slip Ring Top of steering column, below steering wheel
C210 (11 cavities) Lower RH side of steering column
S210
Page-Figure
201- 9-A
201- 6-D
201- 8-B
Main harness, behind RH side of I/P 201- 6-C
B: NONE OF THE HORNS SOUND
Connect:
T E S T
LAMP
At: CONVENIENCE CENTER
Conditions:
• Horn Relay: REMOVED
• Horn
Switch: OFF
Connect
Between
A(ORN)&
Ground
Correct
Indication
Test Lamp
ON
For Diagnosis
Seel
Horn Switch: ON
A(ORN)&B
(BLK)
Test Lamp
ON
See 2
If all the tests yield the correct results,
check the Horns and the DK GRN (29)
wire for an open. If OK, replace the Horn
Relay (see schematic).
Check the ORN (40) wire for an open (see
schematic).
Check the BLK (28) wire and the Horn
Switch for an open (see schematic).
CIRCUIT OPERATION
When the Horn Switch is depressed, one side
of the coil of the Horn Relay is grounded. The
relay is energized. Its contacts close and bat-
tery voltage is applied to the Horns.
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