Chevrolet 70 Series 1970, Service Manual

Page: 768 / 841

CHASSIS ELECTRICAL AND INSTRUMENTS 12-22
1
Speedom eter
7 Engine T em perature Gauge 2 0
Radio Controls
2
T e ll-T a le C luster 8
A ir Gauge 2 1
D ifferen tial Lock Switch
a. L.H. D irection al T e ll-T a le
9 O il P r e s s u r e Gauge
22
Front Brake L im iting Valve
b .D iff. Lock T e ll-T a le
10
F uel Gauge
23 C igarette Lighter
c. Low O il T e ll-T a le
11
V oltm eter
24 W indshield Wiper Control
d. Hot Engine T ell-T a le
12 A ir B rake Gauge 25 Engine R etarder Switch
e. Low A ir T ell-T a le 13 A m m eter
26 Ignition Switch
f. R.H. D irectional T e ll-T a le
14 M arker Blink Switch
27 Engine T em perature Gauge
3 Tachom eter
15 Fan Switch
28 A ir Induction R estrictio n
4 T r a iler Brake Hand Control
16 Light Switch Gauge
Valve
17 M aster C ircuit B reaker 29 Starter Switch
5 T r a iler E m ergency B rake Valve
18 H eater and A ir Conditioning
30 D irection al and Hazard
6
T ractor Parking and Em ergency Controls
Warning Control Switch
Brake Valve
19 Window Lift Switch
T-671 5
Figure 19—Instruments and Gauges on Console (Alum. Tilt Cab Models) (Typical)
F or troubleshooting fu el tank gauge, r e fe r to
"FUEL TANK, LINES, AND GAUGE SYSTEM"
(SEC.
8
A) of this manual.
Fuel gauge is not repairable and m ust be r e ­
p laced a s a unit. NOTE: Sender unit in tank in­
corp orates a 90-ohm r e s is to r strip .
AMMETER GAUGE
The am m eter gauge is identified by "AMP­
ERES" on the instrum ent panel and indicates rate
of charge or discharge battery is receiv in g . The
a m m eter circu itry is sp e c ific a lly calibrated for
eith er the 75 or 105 amp gen erator. The 75 amp
generator u se s a shunt which ca u ses the m eter to
show a charge or a d isch arge rate of 60 am ps full
s c a le . The am m eter for 105-am p generator indi­
ca tes a charge or d ischarge rate of
1 0 0
am ps full
s c a le .
Two fu s e s a re used with the am m eter, one in
each lead . F u se s p rotect w iring from short circu it
dam age. T hese fu se s are located near the cranking
m otor and are mounted in w ater-p roof connectors.
The fu se s should be checked if the am m eter be­
com es inoperative. If the fu se s are found to be s a t­
isfa cto ry a voltm eter should be connected from
ground to each of the term in a ls on the backside of
the am m eter. The v oltm eter should read sy ste m
voltage on both te rm in a ls. If it d o es, the fault lie s
with the am m eter, if not there is an opening in the
w iring.
NOTE: The indicator pointer o f the am m eter
should rem ain at the center lin e when engine is not
operating and a ll e le c tr ic a l equipment is turned off.
AIR RESTRICTION GAUGE
The air re str ic tio n gauge m arked "AIR RE­
STRICTION FILTER” on the instrum ent panel in­
CHEVROLET SERIES 70-90 HEAVY DUTY TRUCK SHOP MANUAL