Turbo Boost Gauge Always Reads High
If turbo boost gauge always reads high, check these items:
Check for damaged White/Black signal wire.
Check for defective boost sensing unit.
Check for defective boost gauge.
Turbo Boost Gauge Inaccurate
If turbo boost gauge is inaccurate, check these items:
Check for loose or corroded connections.
Check for defective boost sensing unit.
Check for defective boost gauge.
TESTING
FUEL GAUGE SENDING UNIT
Capri
Remove rear seat cushion. Disconnect fuel pump/fuel gauge sending unit electrical connector at access cover. Turn ignition on. Fuel gauge
should read empty. Using a jumper wire, connect Yellow fuel gauge wire of vehicle harness connector to ground. Fuel gauge should read full.
If fuel gauge operates as specified, replace fuel gauge sending unit.
Festiva
Remove fuel gauge sending unit from tank. See FUEL SENDING UNIT under REMOVAL & INSTALLATION. Connect an ohmmeter and
check sending unit resistance as indicated in FUEL GAUGE SENDING UNIT RESISTANCE (FESTIVA)
table. Replace sending unit if
resistance is drastically different than specification.
FUEL GAUGE SENDING UNIT RESISTANCE (FESTIVA)
OIL PRESSURE GAUGE (CAPRI)
1. Remove electrical connector from oil pressure sending unit located on right side of engine block. Turn ignition switch on. Oil pressure
gauge should read low. Install a jumper wire between Yellow/Red wire of oil pressure sending unit vehicle harness connector and
ground. Oil pressure gauge should read high.
2. If oil pressure gauge operates as specified, replace sending unit. If gauge does not operate as specified, check instrument panel power
and ground circuits.
OIL PRESSURE WARNING LIGHT (FESTIVA)
Light Stays On With Engine Running
1. Turn ignition on (DO NOT start engine). Disconnect Yellow/Red wire from oil pressure switch connector. Light should go off.
2. If light stays on, repair short in Yellow/Red wire between oil indicator light and oil pressure switch. Reconnect wire to switch. Light
should be on with ignition on. If light does not go off when engine is started, check switch or engine for low oil pressure.
Oil Light Will Not Go On With Ignition On
1. Ground Yellow/Red wire at instrument panel connector. If light goes on, repair Yellow/Red wire between oil pressure switch and
indicator light or replace defective oil pressure switch.
2. If light does not illuminate, check bulb or check instrument panel ground circuit.
TEMPERATURE GAUGE (CAPRI)
1. Remove electrical connector from temperature sending unit located at front of cylinder head. Connect one lead of Gauge System Tester
(021-00055) to connector and other tester lead to ground. Set tester to 18 ohms, turn ignition switch on and observe temperature gauge.
Gauge should read 250°F.
2. Turn tester to 60 ohms. Gauge should read 175°F. Turn tester to 223 ohms. Gauge should read 100°F. If all readings are within twice
the needle width of correct reading, gauge is functioning properly. If readings are not as specified, replace gauge.
TEMPERATURE GAUGE (FESTIVA)
See TROUBLE SHOOTING for possible service areas.
TEMPERATURE SENDING UNIT (CAPRI)
Remove sending unit from engine and place in container of water. Heat water to 176°F (80°C). Measure resistance between sending unit
connector and case. Resistance should be 49.3-57.7 ohms. If resistance is not as specified, replace sending unit. NOTE:Inspect fuel tank for distortion or dam age. If distorted or dam aged, repair or replace tank before testing.
Float PositionOhms
Full Position (Up)Approximately 7
Half-Full Position (Middle)Approximately 33
Empty Position (Down)Approximately 95
Page 3 of 5 MITCHELL 1 ARTICLE - INSTRUMENT PANEL 1991 ACCESSORIES & SAFETY EQUIPMENT Ford Motor Co. Switches
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