Pontiac Fiero 1988 Service Manual page 1086

I N S T R U M E N T PANEL: INDICATORS C L U S T E R
D: FUEL GAGE SHORT TEST
Disconnect Fuel Tank Unit connector. Turn the
Ignition Switch to RUN. Wait 1 minute to allow
the Gage to reach full.
• If Fuel Gage now indicates full, repair/
replace the Fuel Gage Sender.
• If Fuel Gage still indicates empty, check/
repair PNK (30) wires for shorts to ground,
the Instrument Cluster Printed Circuit for
flaws and the Fuel Gage connections.
Replace the Fuel Gage if PNK (30) wires,
Printed Circuit and Gage connections are
OK (see Section 8C).
E: FUEL GAGE SENDER TEST
Disconnect Fuel Tank Unit connector and con-
nect one red clip lead of tester J-33431 to the
PNK (30) wire and the other to ground. Set the
resistance dials of the tester to 0 ohms and then
to 90 ohms. The Fuel Gage should read E and
then F. Wait 1 minute to allow the Gage to reach
Full
• If the Gage responds correctly check the
BLK (150) wire for an open. If OK, replace
the Fuel Gage Sender.
• If the Gage does not respond correctly,
check PNK (30) wire to the Instrument Clus-
ter for high resistance. Also, inspect the
Printed Circuit for proper mating of the con-
nectors. Replace the Fuel Gage if the wire
and Printed Circuit are good (see Section
8C).
F: FUEL GAGE OPEN TEST
Connect: FUSED JUMPER
At: FUEL TANK UNIT CONNECTOR
(HARNESS HALF) (Disconnected)
Condition:
• Ignition Switch: RUN
Jumper
Between
PNK &
Ground
PNK & BLK
Correct Result
Fuel Gage
readsE
Fuel Gage
reads E
For Diagnosis
Seel
See 2
• If the Fuel Gage indicates correctly
repair/replace the Fuel Gage Sender and
its wires.
1. Check/repair PNK (30) wires for opens.
Check Printed Circuit for flaws and for
clean and tight Fuel Gage connections.
Replace Fuel Gage if the above checks are
OK (see Section SC).
2. Check/repair the BLK (150) wire for an
open (see schematic).
G: COOLANT TEMPERATURE GAGE
SHORT TEST
Disconnect the Coolant Temperature Sender/
Switch connector and put the Ignition Switch
in RUN.
© If the Coolant Temperature Gage reads
Cold, replace the Coolant Temperature
Sender/Switch.
• If the Coolant Temperature Gage does not
read Cold, check the Instrument Cluster
Printed Circuit and the LT GRN and DK
GRN/YEL (135) wires for a short to ground
(see schematic). Replace the Coolant Tem-
perature Gage if all wires are good (see Sec-
tion 8C).
H: COOLANT TEMPERATURE GAGE
OPEN TEST
Disconnect the Coolant Temperature Sender/
Switch connector. Jumper the DK GRN/YEL
(135) wire to ground and put the Ignition
Switch in RUN.
• If the Coolant Temperature Gage reads Hot,
replace the Coolant Temperature Sender/
Switch.
• If the Coolant Temperature Gage still reads
cold, check the LT GRN and DK GRN/YEL
(135) wires, Printed Circuit, and Gage con-
nections for an open. If OK, replace the
Coolant Temperature Gage (see Section 8C).
I: COOLANT TEMPERATURE GAGE
ACCURACY TEST
Disconnect the Coolant Temperature Sender
connector. Connect one red clip lead of the
J-33431 tester to the harness connector DK
GRN/YEL (135) wire, and the other red clip lead
to ground. Adjust the resistance dials of the
tester to 1400 ohms and then to 55 ohms. The
Coolant Temperature Gage should show Cold
and then Hot.
(Continued on next page)