Power Switch

The B and M AUTOMOTIVE Power Switch (Model 80217) is a torque converter lockup switch kit engineered for General Motors vehicles equipped with clutch-type torque converters. Designed for TH700R4, TH2004R, TH200C, and TH350C transmissions, this component allows drivers to manually or electronically control torque converter lockup—a critical function that improves fuel economy, reduces transmission heat, and enhances overall drivetrain efficiency. Whether you're building a street machine, restoring a classic truck, or optimizing an existing GM automatic transmission, this lockup switch kit delivers the control serious enthusiasts demand.

This Power Switch operates by engaging the torque converter's internal clutch at highway speeds or under steady-state cruising, effectively creating a mechanical lock between the engine and transmission. This direct coupling eliminates slippage, reduces parasitic losses, and lowers transmission fluid temperatures—all while improving fuel mileage and reducing wear on transmission bands and clutches. The kit is purpose-built for GM's clutch-type converters, ensuring proper electrical and mechanical compatibility with OEM transmission designs. Compact and lightweight at 0.6 lbs, the switch integrates seamlessly into existing wiring harnesses and control systems.

This lockup switch kit is ideal for street rodders, restorationers, and transmission builders working on 1970s through 1990s GM vehicles. It's particularly valuable in applications where OEM lockup controls have failed, been deleted, or where owners want independent management of converter engagement. Installation requires basic electrical knowledge and familiarity with transmission wiring; compatibility is confirmed for TH700R4, TH2004R, TH200C, and TH350C transmissions. Pair this with quality transmission fluid and proper engine tuning for maximum benefit in highway cruising, reducing operating temperatures and fuel consumption significantly.