Toyota Celica Supra 1986 Service And Repair Manual page 592

....
BE-44
BODY ELECTRICAL SYSTEM -Instruments and Sender Gauges
SECTION
TROUBLE
E
511••
t~ome•
Brigh-
does
not
ct..,.
when rtleosU1
is
turned
Only speedometer and tachometer?
Yet
Replace wee<~ometer
No
Yet
I
>
I
Only tachometer?
Remove tachometer and
No
connect sub-harness (SSTI
:
l
Remove meter and connect sub·
(j)With the ignition
SIW
at ON position, check that
harness (SST).
voltage between terminals 4 and 6 of
t~tehometer
connector is more than 3V with rheostat at MAX.
OK
No
{VWith the light SIW turMd ON,
Replace tachometer
I
Replace speedometer
dOH voltage between tenninals 1
and 7 of sub-harness vary from 0
No
@ With the light
SIW
turned ON.doet
to 9V when rheostat is turned?
voltage between terminals T R and E of
Yes
rheostat vary when rheostat is OPerated?
No
Yes
Check rheostat Bad wiring between
(See
page
BE-18 1
rheostat and meter
Remove other meters and check for
No
Replace
wee<~omett<
I
brightness change of
wee<~ometer.
Yes
:
Connect other meters one by one
to find bad meter.
l
Replace bad meter I I '
!
I