Block Buddy

Overview

Block Buddy is a plug-in indicator for engine block heaters. It sits inline between the outlet and the block heater cord, and a built-in LED array lights up when current is flowing. No power, no light — you know before you walk away from the truck. SHAKO designed the electronics and managed the overmolded housing from first article through production tooling.

The challenge

The client, a family trucking operation in Southern Utah, had a real problem: plugging in a block heater and assuming it was working, only to find out otherwise on a cold morning. The electronics needed to sense current across a wide load range — 200 to 1500 watts — with a clean binary response, no flicker, and no false reads. The housing had to be outdoor-rated, overmolded over a live circuit board, and fit the aesthetic vision.

What we did

• Defined the electrical specifications and designed the indicator PCB — a current sensing circuit with a LED array, viewable through the translucent overmold window.
• Evaluated critical design and reliability concerns during prototype testing
• Specified and sourced the overmolded housing and coordinated small batch PCB fabrication
• Procured first-shot and second-shot injection mold tooling and managed first article acceptance

Outcome

A production-ready block heater indicator cable, sold direct-to-consumer through blockbuddycable.com. Rated for rugged outdoor use. Built in the USA.