Description:

E-Tron RU-12 Ballast Resistor: Identification & Details

E-Tron part number RU-12 is a four-terminal ignition ballast resistor designed for point-type distributor systems. It drops coil voltage during normal operation to protect the ignition points and coil, then bypasses during engine start for full coil voltage.2

Specifications

• Part Number: RU-12

• Terminals: 4-prong design for separate feed and return circuits

• Brand: E-Tron (also sold under AutoExtra/Standard Motor Products)

• Condition: New-other (factory seconds or shelf-worn NOS)

• Construction: Durable plastic housing with internal resistance element

Vehicle Fitment

This ballast resistor is most commonly found on late-’60s to mid-’70s Mopar models equipped with breaker-point distributors, including:

• Plymouth Road Runner (1970–1973) with 318 ci and 340 ci V8 engines

• Plymouth Satellite (1970–1972) I6 (225 ci) and V8 (318/340/383/400 ci) engines

• Plymouth Fury (1971–1974) 360 ci and 440 ci V8 engines

• Dodge B100/B200/B300 vans (1971–1974) I6 (198/225 ci) and V8 (318/360/440 ci) engines

• Chrysler Newport/New Yorker/Brougham (1972–1974) with 400 ci and 440 ci V8 engines