cranks but no spark at coil
So the ECU is approx 3 years old, the orange mopar box, 4 pin. 2 post ballast
So battery ref volts is 13.02 (on charger all night). Cranking there were 11.7 V
Test voltage at ballast red wire (unhooked) and key in run 12.78 V
Test voltage at coil +ve with ECU unplugged and cranking. 11.93 V
Not cranking but in run 12.1 V
Test coil-ve ECU unplugged and cranking 10.9 V
Test dist lead (harness side). Male bare dist lead grounded I get spark from coil tower wire when held close to ground key in run position. Didn't do it before?? Or I did the test wrong??
Next has me baffled. Coil wire hooked back up to distributor. Key on and bare male dist lead(harness side) grounded, no spark from lead BUT I can hear one coming from somewhere, just cant pin point it.
Almost 100* out today. Friggin hot
Thanks all for the advice.
I posted a pic of the coil wiring. Manual doesnt show near the wires I have hooked to it (coil -ve) lol.
Good ground at ECU (continuity test)
Distributor leads.
That makes total sense, because the coil field dropping (from the power to it shutting down when you turn the key off) causes a spark.
That's exactly what it should do and tells us that there is power to the coil.
The problem is nothing is telling the power to drop when cranking and the reluctor pickup coil in the distributor is what does that.
The distributor pickup coil sends a signal to the ignition module and the module shuts down the coil ground each time one of the reluctor vanes passes the pickup causing it to spark for each cylinder making the motor run.
This tells us that the either there is no signal coming from the distributor or the ignition module is not seeing it, be it because of a bad connection or bad part. (distr or module)
Do what Del said about touching the exposed connector of the distributor leads on the harness side to ground with the key on.
If you get a spark each time you tap that to ground that tells us that the ignition module works but isn't getting a signal from the distributor.
I like to crimp the two female sockets on the distributor pigtail just to make sure they are contacting.
You are trying to see if the coil is getting voltage. Just hook from coil+ to ground and see if you have voltage in "crank". Would not hurt to double check after key returns to "run" see that you have a lower voltage there, perhaps 7--10V or so.
Do you have a dual ballast? Does it appear the ECU is original? Could be trouble there. The "tap test" earlier should eliminate that
Checking for voltage, simple as that, voltmeter from pink wire to batt neg post. Turn the key to start & crank, there should be Batt. V there.....it's that simple.......
there are voltage variations because of loads on the harness & draw from components, why I was telling You to unplug certain things...takes them out of the equation.
If You are checking this with the terminals plugged onto the ballast, the pink wire WILL have Batt. V~.5V in cranking postion, & 10-10.5V in Run position because Run
voltage will be coming through the ballast resistor.
