Ford TFI-IV / DI Ignition Coil Supply Voltage Test Diagram - Coil (+) Terminal

This document is a single illustration (figure 7.23) from an automotive service manual showing how to measure the ignition coil supply voltage on a Ford TFI-IV or DI (distributor ignition) system. The line drawing depicts an E-core style ignition coil with its connector, and a test probe back-probing the coil's positive (+) terminal, which is called out with an arrow and the label 'POSITIVE (+) TERMINAL.' The probe lead runs to the positive (+) input of an analog voltmeter (marked with a 'V' scale and needle), while the meter's negative (−) terminal is connected to 'ENGINE GROUND,' indicated by a ground symbol. A reader learns the correct hookup for checking whether battery/ignition supply voltage is reaching the coil primary: probe the coil positive terminal with the voltmeter positive lead and ground the negative lead to the engine. The figure caption identifies the test as applicable to TFI-IV or DI ignition systems. No specific voltage specifications, year/model applicability, or part numbers appear in this scan; it is one page of a multi-part TFI coil testing sequence (companion scans cover initial diagnosis and primary/secondary resistance checks).