Engine Block Heaters - GMC G Service Manual

DESCRIPTION
The optional engine block heater is used to preheat
engine coolant for cold weather starting. The unit consists
of a heating coil that fits into the engine block. It has an
attached electrical cord with a plug. If the element fails to
heat the coolant, check the cord and connections before
replacing the element.
ON-VEHICLE SERVICE
REMOVAL
M Remove or Disconnect
1. Coolant. Refer to ENGINE COOLING (SEC. 6B1).
2. Plug end from the heater.
• Loosen the bolt/screw.
3. Heater from the engine block.
INSTALLATION (Figures 35, 36 and 38)
1. Apply a coating of lubricant to the O-ring and to the
cleaned surface of the plug opening in the block.
2. Install the hairpin end of the heating coil into the
opening and push the support in as far as it will go.
3. Position the block heater as shown for the engine in
figure 38.
Tighten
• Bolt/screw to 1.8 N*m (16 in. lbs.).
4. Route the heater cord so that it does not touch the
engine, hot pipes, manifold, or any moving parts.
Refer to figures 37, 39, 40 and 41.
5. Coolant. Refer to ENGINE COOLING (SEC. 6B1).
2. O-ring
3. Yoke
4. Terminal Ground
5. Ground Terminal
Figure 35 — Engine Block Heater

ENGINE BLOCK HEATERS

6. Bolt/Screw
7. Support
A. Positioned
B. Installed
F-02505
ENGINE ELECTRICAL 6D-29
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A. Line parallel to crankshaft centerline.
B. 4.3L, 4.8L Engines
C. 5.0L, 5.7L, and 7.4L Engines
Figure 36 — - Element Position
9. Heater Cord
12. Radiator Support
Figure 37 — Heater Cord Wiring, P-Motorhomes
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F-02504
L00421