Current Draw (Quiescent Drain) - Testing
SECTION: 86No: 68
ELECTRICAL
Model: '90 MY SEDANS
Date: JANUARY, 1990
KEY POINTS:
QUIESCENT DRAIN
A quiescent current test determines if the vehicle's current consumption with the ignition off is within acceptable limits. To perform a quiescent current test on 1990 my sedan, the following procedure should be used:
Test Equipment - Fluke 23 10 amp Digital Multimeter.
^ Disconnect all accessories (i.e. alarm, telephone, radar detector, etc.).
^ Turn off all vehicle switches. Ensure that the passive restraint system is in the front docked position.
CAUTION:
If the two above mentioned steps are not performed, the ammeter internal fuse may fail.
^ Remove the battery negative cable.
^ Connect the meter leads to the COM. and the 10 A test sockets. Set the meter to the DC amps scale.
^ Connect the COM. test lead to the battery negative terminal and the positive test lead to the disconnected battery cable.
^ Observe the quiescent current. It should range from 0.32-0.48 A for approximately the first eight minutes and then decrease significantly. If the current does not drop within eight minutes, investigate the cause.
NOTE:
The initial high quiescent current is caused by the ride leveling system seeking its trim height and the interior lights timing out.
^ Remove the ride leveling fuse # A1 and the interior light fuse # C2 from the right hand fuse panel. Move the positive test lead to the meter 300 mA test socket.
^ Repeat the quiescent current test and observe the quiescent current. For the initial 20 seconds it will be high (less than 300 mA) due to the interior light logic circuit timing out. Current should then settle to 20-40 mA. If the quiescent current is above 40 mA, refer to the fault guide
Quiescent Current Fault Guide:
^ Ensure that all switches are off, including the headrest lights and reading lights (VDP/MAJ only).
^ Remove all fuses, one at a time, from the fuse panels while observing the ammeter. Ensure that the correct order is maintained for reinstallation. If the current flow falls when a fuse is removed, investigate that circuit. Refer to the appropriate wiring diagram and disconnect connectors and components until the cause of the high current flow is found.
^ If the quiescent current is still too high with all the fuse panels removed, repeat the procedure for the in-line fuses.
IN-LINE FUSES
Fuse Location
^ Wiper logic module Right-hand side electrical component panel
^ Radio Under ski slope
^ Radio memory Under ski slope
^ Anti-lock system relay Behind right-hand side fuse box cover
^ Anti-lock pump relay Behind right hand side fuse box cover
^ If the quiescent current is still too high with all fuses removed, disconnect all relays, one at a time, while observing the ammeter. Ensure the correct order is maintained for reinstallation. If the current flow falls when a relay is removed, investigate that circuit. Refer to the appropriate wiring diagram and disconnect connectors and components until the cause of the high current flow is found.
^ If the quiescent current is still too high with all fuses and relays disconnected, the fault is located in one of the direct battery feed circuits.
DIRECT BATTERY FEEDS
^ Alternator
^ Starter
^ Engine management ECU
^ Engine management main relay
^ Air injection relay
^ Fuel pump relay
^ Wiper logic/audible warning module
^ Central processor
^ Anti-lock system relay
^ Anti-lock pump relay
^ Ignition-on relay
Jaguar Approved Accessories-Quiescent Currents:
Alarm System:
SCS-valet switch in center console.
Models:
1990 My Sedans
Quiescent current:
Unarmed 24 mA
Disconnect:
Remove the in-line fuse located behind the left side dash panel.
Telephone:
Panasonic
Models:
All
Quiescent current:
5 mA +/- 3 mA
Disconnect:
Open the transceiver connector at the left of the trunk.