Chevrolet CAMARO 1979 Service Manual page 899

ACCESSORTES 9-3
on all modrls qcepr Lr engrn e equ rpped ! ehicles. k opens
pneumaticalry lvhen the brake pedal is depresseal.
or clo\es Ihe rhrottle as diclâied by the,lrânsducer
4. The Cruise Brake Releâse Switch, ivhich is mounted
on the..brâke pedal bracker. disengâges the system
erecrflca y $hen the brake pedal i, deDfessed.
5 The cruise Brâke Release valv;' which is moùnted
6. The cable ând casing Assemblies drive the
on the brake pedal bracket, disengages the system
t.ansaucer and spe"domet"r.
D I A G N O S I S
ELECTRICAL SYSTEM TROUBLESHOOTING
l. Check fuse and connector.
2. Check brâke eiectric switch as followsl
a. Unplug connecror ar switch.
b. Connect ohmmeter across cruise masrer conracls on
brake switch. The ohmmeter must indicaie no continuity
$hen lhe pedal is depresced and conrinuiry when pedal rs
released. Ihe cruise releâqe brake swirch (eleclric.) is
adjusted âs is rhe standârd stop light brake swirch.
c. Replace brâke electric switch if needed.
3. Check clùtch releâse switch (manuâl rrânsmission
only) same âs electric r€lease swirch above.
Engagement
Switch Test
Check engagemenr swirch and connecting $iring âs
foilows: Unplug engagement switch connector (drown, bilue,
black) at el€ctrical rviring harness connecror then perform
the following resrs (fig. 9-3C).
Test#l{onnect
ohmmeter between terminal #1
(brown wirer and rerminalE2 ôlue wrret. Conrinuiry shall
be mâinlained unlil rw,rch ic depressed a rhe $a) in.
Test#2 Connêct ohmmerer between terminâl#l
(brown wrre) and terminâlFl (black wire). No conrinuily
chall be (hotrnl hoqever. when rhe bu on i, parrially
depressed, continuiry shall be indicared. When me Durron
is pressed all the way down, no conrinuity shall be shown.
Test#3 Connect ohmmerer between terminal#2
(blue wire) and terrninâl#3 (black wire). Button released,
no continuity; however, when the bufton is depressed
partially ând fu1ty, continuiry shâ]i be shown.
Harness Test (Fig. 9.3C)
1. Disconnect engage switch wire harness connecror
from rhe main harn€ss connecror (red, brown/white, and
while wires).
2. Connect ohmmeter between point C (brown,/white
stripe wire in main wire harness) ând ground. Mâke sure
the Trânsducer is well grounded to the chassis. The
ohmrneter should read berweei 42 and 49 ohms. If â
resrstânce either above or below the value indicated is
shown, then disconnect the connector from the Transducer
and measure rhe resistance of rhe bfown,/whire sripe wir€
from poinr C to D. Ir should measure 40 ohms
1l ohms.
3. If a rcsistanc€ eirher above or below the value
indicâted is shown. rhe main wiring harness should be
NOTICE: When disconnecting or reconnecring rhe
main wiring harness connector ftom the Trânsducer,
car€ should be exercised so as not to damage the blâd€
connecto.s or the wiring harness. The disconnect may
be facilirated by prying cârefuily on rhe ptastic
conn€ctor with a small screwdriver.
4. Measuring rhe solenoid coil cjrcuit resistance
between point E (Hold Terminâl) aDd ground, rhe ideal
reslstance should be betwe€n 5 ând 6 ohms. A r€ading of
less than 4 ohms indicat€s shorting in ihe coil circuii A
reading of more than 7 ohms indicates excessrve resrshnce
in the coil circuit. Eithe. extremity jndicates replâcement
ofthe Tûnsducer assembly. Th€ mâin harn€ss wiring from
point F to G (white wire) should also be checked for
contlnuity.
Power Unit and Vacuum System Test
To determine the conditior ofrhe diaphragn, remove
hose from the Powe! Unit and apply 14 inches of vacuum
to the tub€ opening and hold in for one minute. The vacuum
'hâll not leâk dosn more rhân 5 inches of \âcuum in one
minute. If leakage is detected, replâce the Power Uni!. To
utiljze engine as a vâcuum sourc€, proceed as followsl
l. Disconnect Power Unir Linkâge at carburetor ând
vâcuum hose from the Power Unir, then connecr engine
vâcuum directly to the Power Unir fitting.
2. Note position of Power Unir diaphragm.
3. Stârt engine-the diaphrâgm should pull in.
4. Clamp off engin€ vacuun supply line ând check for
leakage.
The cruise release brak€ valve (vacuurn) ând
connecting hoses can likewise be checked using â vacuum
pump.