Chevrolet 70 Series 1970, Service Manual

Page: 576 / 841

ENGINE ELECTRICAL 6Y-3S
Figure 2 0 —A d ju s tin g Point O pening
INSTALLATION
IMPORTANT: Make s u re negative b a tte ry cable
is disconnected fro m b a tte ry .
1. P la ce re g u la to r-to -g e n e ra to r ground w ire
(if used) on re g u la to r mounting and in sta ll re g u la­
to r attaching sc re w s.
2. L ift up on re g u la to r term in al latch and in ­
s e r t w iring h a rn e ss co nnector over re g u la to r te r m ­
in a ls.
IMPORTANT: Make s u re connector is fully
engaged o ver te rm in a ls and locked in position.
Check by attem pting to pull connector a p a rt.
3. Connect b a tte ry cable to b a tte ry te rm in a l.
GENERAL INSPECTION
With the re g u la to r assem b ly on w ork bench,
rem ove the cover (fig. 19) and inspect v ario u s
com ponents, connections, and contact points fo r
sig n s of dam age.
VOLTAGE REGULATOR UNIT CHECK
CLEANING CONTACT POINTS
If the contact points a r e d irty o r oxidized,
they m ust be cleaned b efore any adjustm ents a re
m ade since the cleaning may change the m echan­
ic a l se ttin g s. The upper contacts may develop
sligh t c a v itie s. T hese s u rfa c e s should be cleaned
to b a re m etal with #400 silicon e carb ide p ap e r
o r equivalent folded o v er, then pulled back and
fo rth betw een contacts.
It is not n e c e ss a ry to rem ove the ca v ities en­
tire ly . The low er contacts a r e of s o fte r m ateria l;
u se a p iece of cloth with solvent to rem ove any
d iscoloratio n.
IMPORTANT: DO NOT USE AN ABRASIVE
ON THESE POINTS.
A fte r contacts have been cleaned they should
be w ashed w ith a solvent (non-toxic type) to r e ­
move any foreig n m a te ria l.
Figure 2 J—A dju stin g A ir Gap
CHECKING AND ADJUSTING
CONTACT POINT OPENING
With the low er contacts touching, m easu re the
point opening between the upper contacts a s shown
in fig u re 20. P oint opening should m easu re 0.014".
A djust by bending the upp er contact a rm a s shown.
CHECKING AND ADJUSTING AIR GAP
M easure a ir gap with a 0 .0 5 7 -in c h fe e le r gauge
between the a rm a tu re and the c o re when low er
contacts a r e ju st touching a s shown in fig u re 21.
To adjust the a i r gap, tu rn the adjustm ent nut lo ­
cated on the contact support.
NOTE: Only an approxim ate a i r gap setting
should be m ade by the fe e le r gauge m ethod above.
The final settin g m ust be w hatever is re q u ire d to
obtain the specified difference in voltage between
the up per and low er co ntacts. In stru c tio n s fo r
m aking final settin g a r e explained p rev io u sly . See
"R egulator Voltage T est (On V ehicle)."
FIELD RELAY UNIT CHECK
F ou r checks a r e re q u ire d on the field relay:
Figure 2 2 —A dju stin g Field Relay A ir Gap
CHEVROLET SERIES 70-90 HEAVY DUTY TRUCK SHOP MANUAL