This is a vintage ignition system but we are going to apply the same processes we use today to troubleshoot a no spark conditions on this system. All you need is a simple test light to follow along!
The truck being used is a 1978 Dodge Power Wagon W150

Control Testing Ignition Coils:
No Spark Diagnostics "Control Testing" Part 1 [an ScannerDanner Premium video]    • No Spark Diagnostics "Control Testing...  
No Spark Diagnostics "Control Testing" Part 2 [an ScannerDanner Premium video]    • No Spark Diagnostics "Control Testing...  

00:00 intro
00:47 what system we are working on
01:25 ignition coil voltage readings
02:20 thermal camera view
02:40 primary current flow
05:00 don't leave your key on!
06:40 what no ground on the ICM looks like
08:40 control testing with a test light
12:00 importance of the cranking bypass circuit
17:45 bypass circuit enabled vs disabled during cranking
19:05 what a faulty pickup coil looks like
20:38 pick-up coil bypass test
22:40 resistance test of the pick-up
24:40 me stabbing myself with a pin
25:00 pick-up coil output voltage test
27:35 why I don't like the voltmeter for coil negative control testing
31:20 flow chart for no spark diagnostics on this system
31:45 forum post for access to my flow chart https://www.scannerdanner.com/forum/s...

ScannerDanner Tools:
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For more information on this topic, I have written a “field manual” called Engine Performance Diagnostics which is available at www.scannerdanner.com as an eBook or paper book.
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On ScannerDanner Premium I will bring you right into my classroom at Rosedale Technical College. You will find page for page lectures taken right from my book as well as exclusive classroom type case studies. What is so special about these classroom case studies? I pull live problem vehicles directly into my classroom and we troubleshoot them in real time, using and applying the theory and testing procedures we learn during the classroom lectures. There is no better on-line training of how to troubleshoot automotive electrical and electronics systems anywhere!

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