Jeep UNIVERSAL CJ-2A - Page 146

'J eep' UNIVERSAL and 'Jeep ' DISPATCHER
1-70. PR IMAR Y C IRCUI T
Before t esting t he p rim a ry circuit , mak e ce rta in
that t he ba ttery is satisfactory or i nstall a fully
c harged ba tter y f or the pri mary ci rcuit te sts. Also,
c heck the starter motor f or excessive voltage drop
a nd c heck t he starter motor i tself for exce ssive
d raw.
a . Measure t he vo lta ge at the coil prima ry te rmi-
n als while cranking t he engine with th e starter
motor. If t he vo l tage is l ess t han 4 72 volts with 6-
v olt sy stem or 9 volts with 12 - volt system the
t roubl e will be fo und in t he p rimary c ircuit. If
t here is no voltage at all, check for a break in the
p rimary c1r cui t , possibly in the coil p ri mary wind-
ing .
~ - To check the pri mary ci rcuit , turn t he i gnition
on, t urn t he eng ine until the po in ts are cl osed, and
t hen measu re t he volt ag e d rop acro ss eac h portio n
of t he ci rcuit with a v oltmeter .
10612
FI G. I65 -VO LTAGE D ROP T EST
A- RI GH T WAY-V o ltmeter i odicoting d rop ocro» wire
und co nnec tio ns.
B- WRONG WAY-Vo ltm eter !ndicating d rop ocross wire
o nly . Doe'S no t show b ad co nne ctions.
N ote: Most voltage d rops will be found at the co n-
n ections of wires to terminals as di rt , ox idation,
e tc . ca n cau se ex cessive re sistance at these points.
M easure v oltage drops in wires as shown in Fig.
165 to take this i nto account.
c . Connect the voltmeter f rom t he battery cable
t erminal on t he sta rte r so l enoid t o the bat tery
t er minal of the coil primary. If the voltmeter reads
mo re than 0.2 volt, p er fo rm the c hecks given in
s
teps d, e, and f following.
d .
Co nne ct the volt me ter from t he s olenoid termi-
ual to the b attery t ermina l of t he 1 gnition switch.
If t he voltmeter read s more th en .05 volt, c heck
and cle an t he co nne ctio ns at sol enoid , l ight switch,
and i gnition switch .
e. If t he voltmet er r eading in step d is l ess than
.05 vol t , co nnect t he vol tmeter f rom t he battery
te rmi nal to the i gnition term inal on t he ig nit io n
s
witch. If t he vol tage drop is more tha n 0.1 vol t ,
re pa ir or r eplace the igmtlon switch.
f . If t he voltage d rop in s tep e is not more th an
0.1 rolt, co n nect the vo ltme te r fro m the ig nition
t erminal of the igmtion sw1tch to t he b attery t ermi·
nal of the coil pr ima r y. If the voltmeter reads more
tha n .05 volt, clean and t ighten the co nnec tions
a nd check again. If t he vo ltmeter again reads more
t hen .OS volt, replace t he wire.
g. Connect t he voltmeter f rom the distrib u tor
!) ri mary termi na l on the coil to the coil terminal on
t he di s trib u tor. Voltage dr op should not exceed .05
vol t. Cl ean and tig hten con nections if necessary .
h. Co nnec t t he vol tmeter from t he coil t erminal
on t he distributor to a clean, pai nt -free spot on th e
d
istributo r body. The reading should not exceed .OS
vo lt. If more, it i ndicates ex cessive resi stanc e
t
hrough the points or in t he distributo r internal
con nections. Clean and align the po ints and make
s ure the breaker a rm co nnection to th e p rimar y
t
erminal as well as t he stati o nary contact poi nt
mo unting in t he b ody is clean and tight .
L Ope n t he p oints and c heck t he voltmeter. It
s
hould read cl ose to peak voltage. Low voltage in-
d ica te s t hat a c ircuit t hrough t he d istributor (a
s
hort ) e xists while the poi n ts are open.
j . Disco nne ct th e co ndenser l ead a nd op en t he
p oints. A jump to f ull voltag e indicates a s hor t in
t
he co ndenser. Replace t he condenser. If th ere is
no j ump to full vol tage , o verhaul or replace the
d istributo r.
t< . With t he p oin ts clo sed , connect t he vol tm ete r
f
rom a cl ean , pa int -f ree spo t on the dist ribu tor
b ody to t he negative post of the battery. T he volt-
age dr op sho u ld be p rac t ically z er o, a hardly
r eadable deflect ion on t he voltmeter. If t he vol t-
meter re gi sters a voltag e drop, pe rform t he check s
in
steps 1 and m followi ng.
I. C heck f or voltage d rop in t he battery g roun d
cable . Cl ean t he bat ter y po st, cab le term inals, a nd
co ntact s ur fa ce on the b ellhousing, or on body if
a noticeable deflectio n of the v oltmeter occ urs.
m. Check for any voltage drop betwe en t he dis-
t ributor body and a clean, paint-f ree spot on the
cyl inder block. If t here is any voltage drop, remove
t he d istribut or and cl ean t he moun ti ng surfaces of
d istributor bo dy and cyl inder bl ock.
1- 71. SECONDARY CIRCUIT
If satisfactory i gnition is not obtainable with co r-
r ect point gap and tension ; satisfactory ~ondenser ;
sufficient pri mary voltage; and co rrectly cl eaned,
gapp ed , a nd i nst alled s park plugs; t he secondary
cir cuit should be in vestigated.
a. Te st t he coil. Bring t he co il up to op t!rat ing
t emperature us ing t he coil he at f eature of a co il
t
ester, if av ailab le. Refer to t he coil te ster manu-
f acturer 's instructions f or specific ho ok -up s fo r
perfo rming t he ch ecks gi ven in step s b, c, and d
f
ollowing .
b. Co nn ec t the p ositive l ead . of t he t ester to t he
b
attery t erminal of t he coil prim ary wmd ing . Con-
nect t he te st er gro un d le ad to t he c oil to we r. Mea·
s ure t he resistance of the secondary wi nding. If the
resi stanc e is more th an 20,000 oh ms , a f au lt in th e
se
conda ry wmding is ind icated .
c. C heck for a g roun ded secondary by to uching
t he t es ter gr ound lead to th e coil cover. If res istanc e
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