Ignition Coil Resistance

WARNING: This page is about a different car, the 1995 Mazda 929. However, it is still accessible from the selected car via links, so may be relevant.

Remove primary and secondary leads from ignition coil. Using ohmmeter, check primary resistance between positive and negative terminals of coil. See Fig 1 . Resistance should be as specified in IGNITION COIL RESISTANCE table. If resistance is not as specified, replace ignition coil.
Check secondary resistance between coil towers of each coil. See Fig 2 . See IGNITION COIL RESISTANCE table. If resistance is not within specification, replace coil.
Check insulation resistance of case. Using a 500-volt megger, measure insulation resistance between positive terminal and coil case. If resistance is not more than 10 megohms, replace ignition coil.

Fig 1: Checking Primary Coil Winding Resistance

Courtesy of MAZDA MOTOR CORP.

Fig 2: Checking Secondary Coil Winding Resistance

Courtesy of MAZDA MOTOR CORP.

IGNITION COIL RESISTANCE - Ohms @ 68°F (20°C)

Application

Primary

Secondary

929

⁽¹⁾

9000-17,000

⁽¹⁾	Resistance across side "1" terminals should be 0.7-1.0 ohms, and across side "2" terminals should be 900-1100 ohms. See Figure .