Ford Taurus/Sable 1996-1999 Repair Guide

Diagnosis and Testing



  1. Visually inspect the engine compartment to ensure that all vacuum lines and spark plug wires are properly routed and securely connected.
  3. Be certain that the battery is fully charged and that all accessories are OFF during the diagnosis.
  5. Measure the spark plug wire resistance. Refer to General Information & Maintenance for this procedure.

A simple way to check for proper ignition system operation is the secondary spark test. If however, this test fails to show a spark, the individual components of the system must be tested. Refer to the different components in this section for their testing procedures.


Always turn the key OFF and isolate both ends of a circuit whenever testing for short or continuity.

Always disconnect solenoids and switches from the harness before measuring for continuity, resistance or energizing by way of a 12 volt source.

Electronic modules are sensitive to static electrical charges. If the module is exposed to these charges, damage may result.

Before performing any component testing, check for and if necessary repair the following:

Damaged, fouled, improperly seated or gapped spark plug
Damaged or improperly engaged electrically connections, spark plug wires etc.
Discharged battery
Blown fuses


See Figures 1, 2, 3 and 4

Click image to see an enlarged view

Fig. Fig. 1: This spark tester looks just like a spark plug, attach the clip to ground and crank the engine to check for spark

Click image to see an enlarged view

Fig. Fig. 2: This spark tester has an adjustable air-gap for measuring spark strength and testing different voltage ignition systems

Click image to see an enlarged view

Fig. Fig. 3: Attach the clip to ground and crank the engine to check for spark

Click image to see an enlarged view

Fig. Fig. 4: This spark tester is the easiest to use just place it on a plug wire and the spark voltage is detected and the bulb on the top will flash with each pulse

The best way to perform this procedure is to use a spark tester (available at most automotive parts stores). Two types of spark testers are commonly available. The Neon Bulb type is connected to the spark plug wire and flashes with each ignition pulse. The Air Gap type must be adjusted to the individual spark plug gap specified for the engine. This type of tester allows the user to not only detect the presence of spark, but also the intensity (orange/yellow is weak, blue is strong).

  1. Disconnect a spark plug wire at the spark plug end.
  3. Connect the plug wire to the spark tester and ground the tester to an appropriate location on the engine.
  5. Crank the engine and check for spark at the tester.
  7. If spark exists at the tester, the ignition system is functioning properly.
  9. If spark does not exist at the wire, test the ignition coil, and other ignition system related components or wiring. Repair or replace components as necessary.