Question about Ford Cars & Trucks
1975 Ford F350 360 engine there is voltage at the + side on the coil but i didn't check the - side how do i check the - side? there is know spark at the secondary coil wire.
On a standard external coil, you can use an incandescent test light. ground the test light lead. key on engine off both terminals of the coil should be HOT (light on when you touch either). If the ground is being sent by the module (or PCM on cars where the module is part of the main computer), then when the engine is running or cranking, the light should FLASH if you are holding it to negative while the engine is cranking or running. (Note, it will flash very fast when the car is running, so fast it may look solid if you dont look very carefully). That flashing is the trigger signal pulse grounding the coil to fire it for each cylinder. That in itself is only 1 test, you wont know if its enough ground, too long or short, or if the coil is functional. Its a very simple test using the cheapest of equipment. Proper testing using better equipment will tell you alot more info. But that will tell you if your ignition module is trying to fire the coil. Other issues like crankshaft sensor, theft system, or ignition switch crank-only outputs can cause no spark cranking and are harder to diagnose.
Posted on Jun 26, 2018
A test light clipped to battery positive and the probe tip touched to ignition coil negative while cranking the engine over will blink if receiving pulse signal .
Posted on Jun 26, 2018
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Posted on Jan 02, 2017
Hi, I had the same problem, no spark. I check coil it was good, check the injectors for pulse they are fine, I checked the four wire harnes conected to the distributor are fine, I check resistance at the power transistor in top of the air filter assembly and it was wrong, I just replaced the power transistor and the car is running good again.
I hope this help you.
Posted on Oct 21, 2008
SOURCE: I have a 1995 jetta
This sounds like a bad crank position sensor. The crankshaft position sensor on the AAA engine is located on the "intake" side of the engine block, near the flywheel. Pull that sensor out and see if Auto Zone has a test procedure for it. There is also a chance your ECM fuse is blown. If your service engine soon light comes on when you turn the key on (not starting it) then the fuse is good.
Posted on Dec 05, 2010
SOURCE: Weak or no spark - won't start.
If the coil cannot produce enought spark to jump at least a one inch gap, replace it.
Is the coil internal or external to the distributor?
I’m happy to assist further over the phone at https://www.6ya.com/expert/jeremy_d728a59f986299fa
Posted on Aug 05, 2012
If you hook a test light to battery positive and touch negative terminal on coil and crank engine over does light blink ?
Posted on Jun 22, 2018
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