Thread: 1947 Studebaker Truck w/Chevy 350 No Spark

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Originally Posted by Stude47

The reading was 6.24 volts on the side of the ballast resistor that goes to the positive side of the coil. This was with the key turned on but not cranking. With the engine cranking, the voltage reduces down to 4.30 volts.

That sounds right. The ballast resistor is bypassed while the engine is cranking, it comes into the circuit when the engine is running. When you get it running you'll find the the voltage to be around 6 volts or so. If you have another coil handy swap it in place of the one you have. The primary resistance on most coils is 1.5 ohms or less and is hard without good equipment and since you have confirmed the ballast resistor is good and you're getting no spark out of the plugs that only leaves two things that can be wrong 1. the wire from the coil to the center of the dizzy cap or 2. a bad coil.

Originally Posted by NTFDAY

That sounds right. The ballast resistor is bypassed while the engine is cranking, it comes into the circuit when the engine is running. When you get it running you'll find the the voltage to be around 6 volts or so. If you have another coil handy swap it in place of the one you have. The primary resistance on most coils is 1.5 ohms or less and is hard without good equipment and since you have confirmed the ballast resistor is good and you're getting no spark out of the plugs that only leaves two things that can be wrong 1. the wire from the coil to the center of the dizzy cap or 2. a bad coil.

I swapped out the coil with a new one that I purchased yesterday (2/19/17). Hooked it up and was still getting around 1.4 volts with ignition on, no cranking as before. Due to my lack of electrical experience, I don't understand why I have such a low voltage and not the 12 volts as indicated in the test: https://www.youtube.com/watch?v=PSiw4thM21k. I will see if I can chase down the wiring under the truck this weekend.

Originally Posted by DennyW

Not sure how that is all wired in the vehicle. But, Have you checked all the fuses in the fuse box to make sure they are all good.

All the fuses that I have found all check out.

Originally Posted by DennyW

If you had a skype account, and use your phone, I could look at what you are doing and checking, and maybe give some on the spot help answers, or tips. It's really hard sometimes without being able to see things.

I know what you mean. I don't have a skype account but might be able to send pictures via a personal email. Do you have a email account that I could send this information through? I will be out of town for the next several days and will probably not be able to get back to the truck until this weekend (25th-26th).