GMC 1989 Light Duty Truck, Repair Manual

Page: 688 / 998

6D5-8 DISTRIBUTORS
ohms or more than 1500 ohms while flexing the
leads, replace the pickup coil.
• If the coil does not have an open, check for
ground as shown in step 2. The reading should
be infinite.
4. Resistance of the ignition coil with an ohmmeter.
• Connect the ohm m eter as shown in figure 19,
step 1. The reading should be zero or nearly
zero. If not, replace the coil.
• Connect the ohm m eter as shown in steps 2 and
3. Use the high scale. Replace the coil only if
both readings are infinite.
5. Electrical perform ance of the module. The module
can only be checked with an approved m odule tester,
such as J 24642-F or equivalent. Follow the directions
exactly that come with the tester.
ASSEMBLY OF DISTRIBUTORS
WITH INTEGRAL COILS
|-H"| Install or Connect (Figure 7)
Cap
1. Spring, button (41) and seal (42) into the cap (figure
15). '
2. Coil (21) and wiring into the cap (figure 8).
3. Four bolts holding the coil to the cap.
4. Cover (19) to the cap (23) with two bolts.
Figure 19—Checking the Ignition Coil
Distributor Components
5. Lubricant into the lube cavity of the housing (30) only
if needed.
• Refer to “ S pecifications” at the end of this sec­
tion.
6. Vacuum unit (2) if equipped or plastic retainer.
7. Screws holding the vacuum unit or retainer to the
housing.
8. Pickup coil assem bly (11) into the housing (30).
• Position the assembly over the pin on the vac­
uum unit or retainer.
N O TIC E: If th e arm o f the as s e m b ly is n o t p ro p e rly
in s ta lle d on the p in , th e arm can flo a t a n d cause
the ig n itio n tim in g to vary.
• Secure the assem bly with the C-washer (figure
17).
9. Magnetic shield (if equipped).
10. W iring conectors to the m odule (figure 11).
• Lubricate.
• M odule term inals with a thin coat of petro­
leum jelly to prevent future oxidation.
• Bottom of the m odule and the m odule rest
pad in the housing with silicone grease or
an equivalent heat transfer substance.
NO TIC E: B e sure to th o ro u g h ly c o a t th e b o tto m
o f th e m o d u le . Failure to d o so c o u ld re s u lt in
h e a t dam ag e to th e m o d ule.