Operation CHARM: Car repair manuals for everyone.

Ignition Cable: Testing and Inspection



1. Check spark plug wires for broken insulation and spark plug terminals for corrosion or damage. Replace spark plug(s), If necessary.
2. Using a suitable ohmmeter, measure resistance of each spark plug wire. Resistance values obtained should be as follows:
a. Ignition coil to distributor resistance should be 4.03-9.41 kilo ohms.
b. Number 1 spark plug cable resistance should be 5.96-13.91 kilo ohms.
c. Number 2 spark plug cable resistance should be 5.15-12.01 kilo ohms.
d. Number 3 spark plug cable resistance should be 4.81-11.2 kilo ohms.
e. Number 4 spark plug cable resistance should be 3.73-8.71 kilo ohms. The spark plug cables contain a synthetic conductor which will be damaged if the cables are stretched or kinked. Piercing the cable with a needle or the pointed end of a probe during the test will cause an increase in cable resistance at that point and will result in cable failure.