25 Circuit Classic-Plus Customizable 1969-74 GM Muscle Car Chassis Harness

Painless Performance 25 Circuit Muscle Car Chassis Harness Painless Performance 25 Circuit Muscle Car Chassis Harness
  • Year: 1969 - 1974
  • Make: GM
  • Engine: Carbureted or Any Stand Alone Fuel Injection
  • Trans: Any

This harness is formerly known as our 18 circuit kit. Click here to read about the recent changes.

This 25 circuit harness was designed to fit 1969-1974 GM muscle cars. This harness features a pre-wired factory style bulkhead connector that plugs directly into the back of the fuse block in the factory location. Factory original quick connect terminals are included for the in dash printed circuit board. Pre-terminated plugs for a column mounted ignition switch, dimmer switch, headlights & headlight switch, blower motor, wiper motor, and turn signal switch. Included with this harness you'll also find a detailed manual and each wire is custom printed with the circuit identification as well as using GM color codes for easy installation.

Replacement Engine Harness

11 circuit for underhood section of Painless GM chassis harness 20102. Does not include the bulkhead connector. Note: Will not fit factory GM harness 21001 - only for 20102.

Click the image for more info.

  • Number of Circuits: 24 Circuit - 18 Fuses w/ Horn Relay and Maxi Fuse
  • Harness Length: Factory Fitment
  • Fuse Type: Blade and Maxi Fuse
  • Firewall Passthrough: Bulkhead Connector
  • Color Code Based: Factory GM
  • Circuit Designations: Printed on Wires

  • Connectors Included:

    Ignition switch, dimmer switch, headlight switch, blower motor, wiper motor and turn signal switch, 10SI & 12 SI Alternator, HEI Power and Tach and 20 Extra 56 Series Terminals for use with any Factory GM 56 Series Connector such as Headlight Switch, Wiper Switch or A/C Switch/Blower Motor.

This harness includes circuits for:
A/C & Heat
Accessory / Cigarette Lighter
Accessory / Trunk Light
Backup Lights
Brake Lights
Charging Dome and Courtesy Lights
Electric Choke
Electric Fuel Pump
Emergency Flashers
Fan Relay Activation Power
Fused Power Source
Horn (Relay)
Ignition Coil
Instrument Panel Lighting and Gauges*
Park Lights
Power Door Locks
Power Windows
Radio/Clock (Constant and Switched)*
Tail Lights and License Plate Light
Third Brake Light
Turn Signals
Wipers and Washer Pump

* Including Wires For:
Cigarette Lighter Light
Brake Warning Light
Fuel Gauge
Generator Light
Oil Gauge
Temperature Gauge

The best product I've seen. I've used it twice!! - Ed Alaniz III, 1/10/2010

ASE certified technician - restoring and modernizing my 73 Chevy Nova. Will look forward to purchasing more of your products. - William Davis, 6/7/2009

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