1999 Mercury Cougar No spark at the ignition coil

First, is your check engine light on? If so, then this is the first place to start. If there's no codes, then proceed with the following.

You'll have to check voltage to the coil packs. (You should purchase a service manual for detailed illustrations of the connectors and wires)

***Disconnect the fuel pump relay during this test***

Measure voltage from the "start/run" terminal and ground. (The wiring harness leading to the coil packs) If there's 10+ volts, then hook up a test light from the same terminal and the other terminals in the connector one at a time. Turn the engine over and check the test light. If it blinks steadily, then your computer is telling the coils to fire but they aren't. If it isn't blinking (or voltage measures less than 10 volts at the start/run terminal), then there's a reason why, and you'll have to do further testing of the computer and sensors.

To test the coil packs themselves, you'll have to measure the resistance of each coil. Compare them to the specs in the service manual. If they're out of specs, replace them.

***Note***

Before proceeding with any tests, check that you have good grounds and that none of your wires/connectors on the engine are loose/corroded, etc.