It is a fused circuit, so check the fuse first. The injector should have a hot wire to it when the key is on. Ground a test light and check for the hot wire with key on. If you have that, then move the test light lead to the positive post of the battery, and probe the ground wire terminal of the injector harness-now have someone crank the car over and check for a blinking light. If the light is blinking when cranking, the ground circuit is good. See? The injector always has power to it with key on. When the computer grounds the injector circuit for a split second, power is passed across the injector solenoid terminals causing it to pulse.
Answers & Comments
It is a fused circuit, so check the fuse first. The injector should have a hot wire to it when the key is on. Ground a test light and check for the hot wire with key on. If you have that, then move the test light lead to the positive post of the battery, and probe the ground wire terminal of the injector harness-now have someone crank the car over and check for a blinking light. If the light is blinking when cranking, the ground circuit is good. See? The injector always has power to it with key on. When the computer grounds the injector circuit for a split second, power is passed across the injector solenoid terminals causing it to pulse.