That means the power relay for the Engine Computer is turning on.
Spark timing is initiated by a camshaft position sensor inside the distributor. That signal goes to the Engine Computer. That computer calculates ignition timing, then sends a signal to the ignition control module which is on the left inner fender. That module triggers the ignition coil. Start by checking the wiring between all of those items.
Without specialized diagnostic equipment there is no way to test the individual components. The way to start is always by reading the diagnostic fault codes. That was real easy to do on Chrysler products starting in the mid 1980s by just cycling the ignition switch. By the early 1990s you can do that on Fords too, but the procedure is a lot more complicated. To start with, you must fashion a jumper wire and connect it as shown by my red oval. This diagram is from Mitchell ProDemand. This shows an older-style analog voltmeter to read the pulses of the sweep hand, but you should be able to count the flashes of the Check Engine light instead. This is where it gets stupidly complicated.
The codes are three-digit codes and you'll be counting flashes or needle sweeps corresponding to each digit. Rather than retyping everything, here's a copy from ProDemand. See if you can follow this and get some fault codes. Without codes you'll need a scanner or you'll have to fall back on replacing random parts, and we never approve of that.
KOEO & KOER SELF-TEST Codes
PCM outputs codes one digit at a time. These codes indicate current faults in system and should be serviced in order of appearance. Use DIAGNOSTIC TROUBLE CODE REFERENCE CHART to identify correct CIRCUIT TEST.
If using an analog voltmeter or Malfunction Indicator Light (MIL), pay careful attention to length of pauses in order to read codes correctly. Digits in DTC will be displayed by a needle pulse sweep (analog voltmeter) or a flash (MIL).
Diagnostic Trouble Codes (DTCs) are represented by a 3-digit number. For example, the first digit of DTC 312 would be displayed by 3 sweeps/flashes with a 0.4-second pause in-between each sweep/flash. A 2-second pause will occur between first and second digits of DTC. Second digit of DTC 312 will be displayed by one sweep/flash then another 2-second pause. Third digit of DTC 312 will be displayed by 2 sweeps/flashes with a 0.4 pause in-between each sweep/flash. A 4-second pause occurs between each code. See Fig 1. KOEO codes are separated from Continuous Memory codes by a 6 to 9-second delay, a 0.4-second sweep/flash (separator pulse) and then another 6 to 9-second delay. See Fig 2.
Scan tester, if used, will count pulses and display them as a digital code. STAR tester cannot be used to read 3-digit codes. Super STAR II or New Generation STAR tester can be used to read 3-digit codes. If using Super STAR II tester, 3-digit codes will only be displayed in fast code mode. If slow code mode is used, display will be blank.
Monday, January 25th, 2016 AT 12:39 PM