American Autowire - 1970-1972 Engine Wire Harness-GM Truck - 20795H

DESCRIPTION

American Autowire - 1970-1972 Engine Wire Harness-GM Truck - 20795H

Replacing worn-out engine wiring or converting your classic Chevy truck to electronic ignition? This 1970–1972 Chevrolet V8 Engine Wiring Harness from American Autowire is designed for trucks equipped with a V8 engine, manual transmission, and HEI ignition.

Part 20795H belongs to American Autowire's Factory Fit line of original-style replacement wiring harnesses. It follows the factory wiring layout while incorporating the changes needed for a compatible HEI distributor.

Unlike an original points-ignition harness, this version replaces the factory resistance wire with a standard 12-volt ignition feed. It also includes a connector designed for a GM large-cap HEI distributor.

Each harness arrives fully assembled and taped, connects at the original firewall location, and follows factory-style routing through the engine compartment.

Whether you're restoring a 1970 Chevy C10, replacing damaged engine wiring on a 1972 pickup, or upgrading your V8-powered truck to HEI ignition, this harness provides an application-specific replacement.

Manufacturer: American Autowire
Manufacturer Part Number: 20795H
Product Type: Engine Wiring Harness
Product Line: Factory Fit
Vehicle Years: 1970–1972
Vehicle Application: Chevrolet Trucks
Engine Application: V8
Transmission: Manual
Ignition Configuration: HEI Electronic Ignition
Ignition Feed: Standard 12-Volt Feed
Distributor Connector: GM Large-Cap HEI
Quantity: Sold Individually

Features

• Designed for 1970–1972 Chevrolet truck applications

• Intended for V8 engines with manual transmissions

• Modified for HEI electronic ignition

• Replaces the original ignition resistance wire with a standard 12-volt feed

• Includes a connector for a GM large-cap HEI distributor

• Manufactured by American Autowire

• Part of the Factory Fit replacement wiring line

• Manufactured according to original GM specifications

• Fully assembled and taped

• Connects at the original firewall location

• Follows factory-style engine compartment routing

• Helps replace aging, damaged, or previously modified engine wiring

Vehicle Fitment

1970–1972 Chevrolet C-Series – 2WD Trucks

Potential applications include:

• 1970–1972 Chevrolet C10

• 1970–1972 Chevrolet C20

• 1970–1972 Chevrolet C30

1970–1972 Chevrolet K-Series – 4WD Trucks

Potential applications include:

• 1970–1972 Chevrolet K10

• 1970–1972 Chevrolet K20

Required Vehicle Configuration

This harness is intended for trucks equipped with:

• 1970–1972 Chevrolet truck electrical configuration

• V8 engine

• Manual transmission

• HEI electronic ignition

• Compatible factory firewall wiring connections

Important: American Autowire lists part 20795H for 1970–1972 Chevrolet trucks with V8 engines and manual transmissions. Verify your specific engine, ignition system, and electrical connections before ordering.

Designed for HEI Electronic Ignition

What Is HEI Ignition?

HEI stands for High Energy Ignition.

GM developed HEI electronic ignition as an alternative to conventional breaker-point ignition systems.

HEI distributors are a popular upgrade for classic Chevrolet V8 engines because they eliminate the periodic adjustment and replacement of ignition points.

Standard 12-Volt Ignition Feed

Original points-ignition systems commonly use resistance in the ignition feed circuit to limit current through the ignition coil.

A typical GM large-cap HEI distributor requires a suitable 12-volt ignition power supply instead.

American Autowire modifies part 20795H by replacing the original resistance wire with a standard 12-volt feed.

This modification accommodates the ignition power requirements of a compatible HEI distributor.

GM Large-Cap HEI Connector Included

Part 20795H includes a connector designed for a GM large-cap HEI distributor.

This makes it a convenient option for compatible Chevrolet V8 trucks being converted from conventional points ignition to a GM-style HEI distributor.

What If I Have an Aftermarket Distributor?

Not all aftermarket electronic ignition systems use the same connectors or electrical requirements.

American Autowire notes that if you're using a distributor other than a GM large-cap HEI unit, the connector may need to be replaced.

Verify your distributor manufacturer's specifications before installation.

Designed for V8 Engines

Chevrolet V8 Application

American Autowire identifies part 20795H for 1970–1972 Chevrolet trucks equipped with V8 engines.

Engine wiring requirements can vary depending on the engine configuration and the location of electrical components.

Selecting the correct engine harness helps maintain compatibility with your truck's electrical system.

What If My Truck Has a 396 V8?

American Autowire also offers part 21945H, specifically listed for 1970–1972 Chevrolet trucks equipped with a 396 V8, manual transmission, and HEI ignition.

If your truck has a 396 V8, verify whether part 21945H is the correct harness before ordering.

What If My Truck Has a Six-Cylinder Engine?

Part 20795H is intended for V8 applications.

Six-cylinder trucks require a harness designed for their engine configuration.

What If My Truck Has an Engine Swap?

If your truck has undergone an engine swap, verify the installed engine's wiring connections, ignition requirements, and compatibility with the factory firewall connection.

Designed for Manual Transmission Applications

American Autowire specifically lists part 20795H for trucks equipped with manual transmissions.

Why Does Transmission Type Matter?

Engine wiring harnesses can differ between manual and automatic transmission configurations.

Depending on the vehicle, electrical connections and wiring arrangements may vary.

Selecting the correct harness helps maintain compatibility with the truck's electrical system.

What If My Truck Has an Automatic Transmission?

American Autowire offers part 31520H for 1970–1972 Chevrolet trucks equipped with a V8 engine, automatic transmission, and HEI ignition.

If your truck has an automatic transmission, verify whether part 31520H is the correct application before ordering.

Factory Fit Replacement Wiring

Manufactured to Original GM Specifications

American Autowire manufactures its Factory Fit engine harnesses according to original General Motors specifications.

This helps maintain the original-style electrical layout of your classic Chevrolet truck while accommodating the HEI ignition modification.

Fully Assembled and Taped

Each harness arrives fully assembled and taped, eliminating the need to construct an engine wiring harness from individual wires and terminals.

Original Firewall Connection

The harness is designed to connect at the original firewall location.

Factory-Style Engine Compartment Routing

The harness follows original-style routing through the engine compartment, helping maintain a factory-style appearance.

What Does an Engine Wiring Harness Connect?

Engine harness circuits vary depending on the vehicle's model year and equipment.

Depending on the application, an engine harness may contain wiring associated with:

• Ignition system

• Starter

• Heater blower

• Engine temperature sending unit

• Oil pressure sending unit

Important: Not every circuit is included in every harness. Consult your factory service manual or American Autowire to confirm the exact connections included with part 20795H.

Why Replace Your 1970–1972 Chevy Truck's Engine Wiring Harness?

Replace Deteriorated Original Wiring

Engine compartment wiring is exposed to heat, vibration, moisture, and contaminants.

Over time, insulation can crack, terminals can corrode, and electrical connections can deteriorate.

Replacing an aging harness provides an alternative to repairing multiple damaged wires individually.

Accommodate an HEI Ignition Conversion

If you're converting your Chevrolet V8 from points ignition to HEI, this modified harness provides a standard 12-volt ignition feed and GM large-cap distributor connector.

Maintain Transmission Compatibility

Part 20795H is designed for manual transmission applications.

Maintain an Original-Style Appearance

American Autowire's Factory Fit harnesses are designed for restorations where original-style wiring connections and routing are important.

Important Fitment & Installation Information

• Designed for 1970–1972 Chevrolet truck applications.

• Intended for V8 engines.

• Requires a manual transmission configuration.

• Modified for HEI electronic ignition.

• Includes a standard 12-volt ignition feed instead of the original resistance wire.

• Includes a connector for a GM large-cap HEI distributor.

• Other distributor styles may require connector modifications.

• Trucks retaining original points ignition should use the appropriate non-HEI harness.

• Automatic transmission applications require a different harness.

• Six-cylinder applications require a different harness.

• The 396 V8 manual HEI configuration has a separately listed harness, part 21945H.

• Verify compatibility if your truck has undergone an engine or transmission swap.

• Confirm original firewall connections before ordering.

• This is an engine wiring harness, not a complete vehicle wiring kit.

• Front lighting, dash, and rear lighting harnesses are separate components.

• Consult your factory service manual and distributor manufacturer's installation instructions.

Frequently Asked Questions

Will this engine wiring harness fit my 1970 Chevy C10?

It may fit if your 1970 Chevrolet C10 has a compatible V8 engine, manual transmission, HEI ignition, and the correct factory electrical connections.

Does this harness fit a 1972 Chevy C10?

American Autowire lists part 20795H for 1970–1972 Chevrolet trucks. Verify your truck's engine, transmission, and ignition configuration before ordering.

What engine is this harness designed for?

American Autowire identifies part 20795H for Chevrolet V8 applications.

For a 396 V8, verify the separately listed part 21945H.

Will this harness fit a six-cylinder engine?

No. Part 20795H is intended for V8 applications.

Does this harness work with an automatic transmission?

Part 20795H is listed for manual transmission applications.

If your truck has an automatic transmission, see American Autowire part 31520H.

Does this harness provide a 12-volt ignition feed?

Yes. American Autowire replaces the original ignition resistance wire with a standard 12-volt feed.

Does this harness include an HEI distributor connector?

Yes. It includes a connector for a GM large-cap HEI distributor.

Will this harness work with my original points distributor?

This harness is modified for HEI ignition.

For an original points distributor, use the appropriate non-HEI engine wiring harness.

Can I use this harness with an aftermarket HEI distributor?

Possibly. Distributors other than GM large-cap HEI units may require connector modifications.

Verify compatibility with your distributor manufacturer before ordering.

Does this harness include an HEI distributor?

No. This product is an engine wiring harness. The distributor is sold separately.

Will this fit a GMC pickup?

American Autowire lists part 20795H for Chevrolet trucks. GMC compatibility has not been confirmed.

Does this replace the entire truck wiring system?

No. This product replaces the engine wiring harness. Other vehicle wiring harnesses are separate components.

Restore Your Chevy Truck's Engine Wiring

Whether you're restoring a classic C10, replacing deteriorated engine wiring, or converting your V8-powered Chevrolet pickup to HEI electronic ignition, the American Autowire 20795H Engine Wiring Harness provides an original-style replacement designed for your truck's specified engine and transmission configuration.

Find the wiring harnesses, electrical components, and restoration parts you need at Tuckers Classic Auto Parts.

Helping Keep Classic Trucks on the Road Since 1993.