lexus LS400 1994 Repair Manual Information / 1994 LS400: ELECTRICAL COMPONENTS

SECTION 6 – 4
217
SERVICE PROCEDURES AND
SPECIFICATIONS
Electrical components
Specifications218 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Checking battery condition and fluid level222 . . . . . . . . . . . . . . . . . . .
Battery recharging precautions224 . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Checking and replacing the blade type fuses224 . . . . . . . . . . . . . . . .
Checking the circuit breakers226 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Checking the cartridge type fuses226 . . . . . . . . . . . . . . . . . . . . . . . . . .
Replacing the windshield wiper blades227 . . . . . . . . . . . . . . . . . . . . . .
Adding washer fluid230 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Replacing light bulbs231 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

ELECTRICAL COMPONENTS
Engine compartment
(fuses)
Driver’s side kick panel
(fuses and circuit breakers)
Driver’s side kick panel
218
SPECIFICATIONS
− FUSES AND CIRCUIT BREAKER LOCATIONS− FUSES AND CIRCUIT BREAKERS

ELECTRICAL COMPONENTS
Engine compartment
219

ELECTRICAL COMPONENTS
220
NO.FUSEAMPERECIRCUIT
1STOP25Stop lights, cruise control
system cancel device
2FOG15Fog lights
3ECU-B15
SRS, Lexus ride control system,
anti-lock brake system, cruise
control system
4RADIO7.5
Radio, cassette tape player,
compact disc player, power
antenna, power rear view
mirrors, air conditioning system
5CIG15Cigarette lighter, theft deterrent
system, shift lock system, SRS
6MIR-HTR10Outside rear view mirror
defogger
7GAUGE10
Gauges and meters, service
reminder indicators and warning
buzzers (except discharge and
open door warning lights),
back-up lights, electronically
controlled automatic transmission
system, automatic transmission
overdrive system, power
windows, seat belt warning lights
8ENGINE7.5Charging system
NO.FUSEAMPERECIRCUIT
9ECU-IG15
Cruise control system, power
steering control system, shift lock
system, anti-lock brake system,
power door lock system, Lexus
ride control system, automatic
light control system
10TURN7.5Turn signal lights
11HEATER15
Air conditioning system, rear
window defogger, electronic
cooling fan system
12WIP20Windshield wipers and
washer, headlight cleaner
13TAIL15
Tail lights, parking lights,
side marker lights, license
plate lights
14PANEL7.5
Instrument panel lights, air
conditioning control system,
clock, instrument panel lights,
glovebox light for light system
15IGN10
Discharge warning light,
sequential rnultiport fuel
injection system, electronic
cooling fan system, SRS
16ST7.5
Starting system, cruise
control system, multiport
fuel injection system,
instrument panel lights
17TRAC15Traction control system

ELECTRICAL COMPONENTS
221
NO.FUSEAMPERECIRCUIT
18RADIO
NO. 120Radio, cassette tape player,
compact disc player, power antenna
19HAZ-HORN15Emergency flashers, horns
20DOME10
Interior light, personal lights, door
courtesy lights, ignition switch light,
open door warning light, trunk
room light, electric moon roof
system, radio cassette tape player,
compact disc player, preset
steering system, seat belt warning
system, air conditioning system,
inside rear view mirror, door lock
and theft deterrent system foot
light, power rear view mirror,
locking, with wireless remote
control system, automatic light
control system
21TEL15Telephone
22EFI20Multiport fuel injection system
23SEAT HTR20Seat heater
24AIRSUS20Lexus ride control system, height
control system
25DRL10Vehicles sold in Canada
Daytime Running Light System
26
HEAD LH15Vehicles sold in U.S.A.
Left-hand headlight
HEAD
LH-LWR10Vehicles sold in Canada
Left-hand headlight (low beam)
NO.FUSEAMPERECIRCUIT
27
HEAD RH15Vehicles sold in U.S.A.
Right-hand headlight
HEAD
RH-LWR10Vehicles sold in Canada
Right-hand headlight (low beam)
28HEAD
LH-UPR15Vehicles sold in Canada
Left-hand headlight (high beam)
29HEAD
RH-UPR15Vehicles sold in Canada
Right-hand headlight (high beam)
NO.CIRCUIT
BREAKERAMPERECIRCUIT
30P/W30
Preset steering, power shoulder
anchor, electric moon roof, power
windows
31DOOR30
Theft deterrent system, seat
control system, fuel opener
control system
32DEFOG40Rear window defogger

ELECTRICAL COMPONENTS
222
CHECKING BATTERY CONDITION
AND FLUID LEVEL
CAUTION:
BATTERY PRECAUTIONS
The battery produces a flammable and explosive
hydrogen gas.

Do not cause a spark by contacting the battery
terminals with tools.

Do not smoke or light a match near the battery.
The electrolyte contains poisonous and corrosive sulfuric
acid.

Avoid contact with eyes, skin or clothes.

Never inhale or swallow electrolyte.

Wear protective safety glasses when working near the
battery.

Keep children away from the battery.
EMERGENCY MEASURES

If electrolyte gets in your eyes, flush your eyes with
clean water for at least 15 minutes and get immediate
medical attention. If possible, continue to apply water
with a sponge or cloth while en route to the medical
office.
If electrolyte gets on your skin, thoroughly wash the
contacted area. If you feel a pain or burn, get medical
attention immediately.

If electrolyte gets on your clothes, there is a possibility
of its soaking through to your skin, so immediately take
off the exposed clothing and follow the procedure
above, if necessary.

If you happen to swallow electrolyte, drink a large
quantity of water or milk. Follow with milk of magnesia,
beaten raw egg or vegetable oil. Then go immediately
for emergency help.
Extended maintenance
interval batteryHold-down clamp
Terminals
1. Check the battery for corroded or loose connections,
cracks, or loose hold-down clamps.
a. If the battery is corroded, wash it off with a solution of warm
water and baking soda. Coat the terminals with grease to
prevent further corrosion.

ELECTRICAL COMPONENTS
223 b. If the connections are loose, tighten the clamp bolts − but
do not overtighten.
c. Tighten the hold-down clamp only enough to keep the
battery firmly in place. Overtightening may damage the battery
case.
NOTICE:

Make sure the engine and all accessories are turned
off before performing maintenance.

Remove the ground cable first and reinstall it last.

Be careful not to cause a short circuit with tools.

Take care no solution gets into the batery when
washing it.
Blue
Red
White
2. Check the indicator as shown.
BLUE − Good condition.
RED − Add distilled water.
WHITE − Charging necessary.If the indicator is red, check the electrolyte level as shown.
a. When checking the electrolyte level, remove the vent plugs
and look at all six cells, not just one or two.
b. Replenish the battery with distilled water.
c. After replenishing, be sure to securely retighten the vent
plugs.
NOTICE:

Do not overfill the battery or the electrolyte may squirt
out of the battery during periods of heavy charging,
causing corrosion or damage.

In order to maintain full engine performance and to
make sure the cover fits the battery, when replacing
the battery use an Exide Group 27F CCA580A battery
or equivalent performance battery.

Use a cover on the battery for longer life.

ELECTRICAL COMPONENTS
224
BATTERY RECHARGING
PRECAUTIONS
During recharging, the battery is producing hydrogen
gas.
Therefore, before recharging:
1. Remove the vent plugs.
2. If recharging with the battery installed on the vehicle, be
sure to disconnect the ground cable.
3. Be sure the power switch on the recharger is off when
connecting the charger cables to the battery and when
disconnecting them.
CAUTION:
Always charge the battery in an unconfined area. Do not
charge the battery in a garage or closed room where there
is insufficient ventilation.
NOTICE:
Never recharge the battery while the engine is running.
Also, be sure all accessories are turned off.
CHECKING AND REPLACING THE
BLADE TYPE FUSES
Driver’s side kick panel
Engine compartment
Spare fuses
Pull-out tool
1. Turn the ignition switch off and open the fuse box lid.

ELECTRICAL COMPONENTS
225 Determine which fuse may be causing the problem. The lid of
the fuse box shows the name of the circuit for each fuse.
2. Make sure the inoperative component is turned off. Pull
the suspected fuse straight out with the pull-out tool and
check it. If it has blown, push a new fuse into the clips.
a. Look carefully at the fuse. If the thin wire is broken, the fuse
has blown. If you are not sure or if it is too dark to see, try
replacing the suspected fuse with one of the same value that
you know is good.
b. Install only a fuse with the amperage rating designated on
the fuse box lid.
GoodBlown
If you do not have a spare fuse, in an emergency you can pull
out the “CIG”, “RADIO”, “DOME” or “HEATER” fuse, which
may be dispensable for normal driving, and use it if its
amperage rating is the same.
If you cannot use one of the same amperage, use one lower
than, but as close as possible to, the amperage. If the
amperage is lower than that specified, the fuse might blow out
again but this does not indicate anything wrong. Be sure to get
the correct fuse as soon as possible and return the substitute
to its original clips.
It is a good idea to purchase a set of spare fuses and keep them
in your vehicle for emergencies.
If the new fuse immediately blows out, there is a problem with
the electrical system. Have your Lexus dealer correct it as
soon as possible.
CAUTION:
Never use a fuse with a higher amperage rating, or another
object, in place of a fuse. This may cause extensive
damage and possibly a fire.

ELECTRICAL COMPONENTS
226
CHECKING THE CIRCUIT
BREAKERS
Driver’s side
kick panel
Circuit breakers
In the event the defogger, air conditioning, power
windows, power door locks, or moon roof does not
operate, check its circuit breaker (C
.B).
To reset the circuit breaker, first turn the ignition switch off and
carefully insert a thin object, such as a toothpick, needle or
safety pin, into the hole in the circuit breaker and push until you
hear a click. The component should now operate. This may be
done without removing the circuit breaker.
If the circuit breaker immediately goes off again or the
component does not operate, turn off the component switch
and have the electrical system checked by your Lexus dealer
as soon as possible.
CHECKING THE CARTRIDGE TYPE
FUSES
GoodMelted
If the headlights or other electrical components do not
work and the blade type fuses are O.K., check the
cartridge type fuses. If any of the cartridge type fuses are
melted, they must be replaced.
If there is an overload in the circuits from the battery, the fuses
are designed to melt before the entire wiring harness is
damaged.
NOTICE:
Before replacing the fuses, have the cause of electrical
overload determined and repaired by your Lexus dealer.
CAUTION:
Always use a genuine Lexus fuse or equivalent for
replacement. Never install an ordinary wire − even for a
temporary fix. This may cause extensive damage and
possibly a fire.