No relay for those functions. The switching is all controlled by the power module which is half of what today is the engine computer. I have a diagram of the circuit that shows the 12 volts for the fuel pump and ignition coil are tied together on the dark green/black wire, and are fed right from the module. I hope it is big enough so you can read it.
You did not list a symptom so I am guessing you have a crank/no-start with a bad fuel pump. The very first thing you need to do is check for spark. By far most no-starts are caused by a loss of fuel, injector pulses, and spark. If you have spark during cranking, the entire computer circuit is working and the best suspect is a failed fuel pump. Do not look to fuel pressure for a clue if spark is missing. The fuel pump should still run for one second when you turn on the ignition switch. That will keep fuel pressure up to normal.
The best test is to connect a test light to the positive terminal on the ignition coil. You should see it light up for one second when you turn on the ignition switch. You should also hear the hum of the pump at that time. What is important is that light should turn on again during cranking. If it does not, suspect the pick-up assembly under the rotor in the distributor. Those used to have a real high failure rate. The signal from that sensor is what tells the module to turn on the 12 volts to the ignition coil, fuel pump, injector, and alternator field.
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Sunday, August 12th, 2018 AT 10:45 PM
