Chevrolet 10 Series 1970, Service Manual

Page: 577 / 671

ELECTRICAL—BODY AND CHASSIS 12-15
Flatface Cow l M odels (Fig. 1 0)
1. Rem ove instrum ent clu ster assem bly as p reviou sly
d escrib ed in this section.
2. Uncrim p b e ze l (7 p laces) and rem ove b e ze l.
3. Rem ove 2 nuts securing tem perature gauge to clu ster
case and rem ove gauge.
4. To in sta ll, re v e r s e rem o va l procedure and check
operation o f unit.
Tilt Cab M odels
1. R em ove instrum ent clu ster as p reviou sly d escrib ed
in this section.
2. R em ove term in al nuts; c a re fu lly rem ove tem perature
gauge.
3. T o in stall, re v e r s e rem o va l procedu re and check
operation o f unit.
T E M P E R A T U R E SEN D ER U N IT R E P L A C E M E N T
A ll M o d e ls
1. R e lie v e coolant system p ressu re by loosening ra d ia ­
tor cap.
2. R em ove sender unit (located in the le ft cylin d er head
on V8 engines, and in the cylin d er head r e a r exhaust
p ort on L -6 engines). R eplace with new unit.
3. Check coolant system le v e l and operation o f unit.
O IL PRESSURE IN D IC A T O R L IG H T
1 0 -3 0 C onventional Cab M odels, Tilt
Cab M odels
If the ligh t does not com e on when the ignition switch
is turned on, o r if the light com eson and rem ains on after
the engine is started, one o r m ore o f the follow in g condi­
tions is indicated:
Low o il p ressu re
D efective w irin g o r sender unit
D efective bulb
High engine tem perature
O IL A N D / O R A IR PRESSURE G A U G E
R E P L A C E M E N T
4 0 -6 0 C onventional Cab M odels (Figs. 12, 14)
1. D isconnect battery ground cable.
2. D isconnect o il p ressu re and a ir p ressu re (i f so
equipped) gauge feed pipes.
NOTE: O il p ressu re lin e conn, may leak oil
when opened; wrap with cloth.
3. Rem ove three (3) re a r c o v e r retaining screw s. Tip
c o v e r and gauge assem bly and rem ove fro m in stru ­
ment clu ster housing.
4. R em ove pipe fittin g and retaining nut fro m gauge
being replaced and rem ove gauge fro m c o v e r.
Installation
1. Install gauge to c o v e r with retaining nut and pipe
fitting.
2. R ein stall gauge in instrum ent clu ster housing. In­
sta ll retaining screw s.
NOTE: Make sure printed circ u it edge is not
pinched between c o v e r and clu ster housing.
3. Reconnect feed lin es to gau ge(s). Connect battery
ground cable.
Flatface Cow l M odels, Including P Models
1. R em ove instrum ent clu ster assem bly as p revio u sly
d escribed in this section.
2. Uncrim p b e z e l (7 p laces) and rem ove b ezel.
3. R em ove nut securing o il p ressu re gauge to clu ster
case and rem ove gauge.
4. To in stall, re v e r s e rem o va l procedure and check
operation o f unit.
OIL PRESSURE SENDER UNIT REPLACEMENT
All M odels
1. Disconnect w irin g harness connector fro m sender
unit term in al (located in block above s ta rte r on L -6
engines and at le ft fron t o f distribu tor on V -8 en­
gines).
2. R em ove sender unit using T ool J-21757, rep lace with
new unit and check operation.
GENERATOR IN D IC A TO R
1 0 -3 0 Conventional Cab M odels,
Tilt Cab M odels
Ignition on, engine not running and tellta le ligh t o ff:
1. Indicator bulb burned out; rep la ce bulb.
20 Open circ u it o r loose connection in the te llta le light
c ircu it.
T e llta le ligh t stays on a fte r engine is started; r e fe r to
Charging System s under Engine E le c tric a l, Section 6Y.
AMMETER GAUGE REPLACEMENT (Figs. 9, 12, 14)
4 0 -6 0 Conventional Cab M odels
1. Rem ove instrum ent clu ster assem bly and lam inated
c ircu it as p revio u sly d escribed in this section.
2. R em ove term in al nuts retaining printed circ u it to
gauge unit.
3. R em ove three attaching screw s, c o v e r and gauge a s ­
sem bly fro m clu ster housing.
4. R em ove term in al attaching nuts and gauge unit fro m
c o v e r plate.
5. To in stall, r e v e r s e rem ova l procedu re and check
operation o f unit.
AIR PRESSURE GAUGE REPLACEMENT
Flatface Cowl and Tilt Cab M odels
1. Unsnap socket and bulb fro m top o f gauge housing.
2. Disconnect a ir pipe at re a r o f gauge.
3. Rem ove two attaching nuts, w ashers and clam p. Pu ll
gauge fro m opening in instrum ent panel.
4. To in stall, re v e rs e re m o v a l procedu re and check
operation of unit.
CHEVROLET TRUCK SERVICE MANUAL