Unanswered Questions

[Shad]

So I am trying to determine if the wires are sound on my ignition system, maybe a bit overkill but I’m learning that the more things you know are right the less”it could be’s” there are.

The trouble I am having is that some of the questions I have, a.) I’m not sure they need to be asked b.) I don’t know where to find the answers to them.

2 examples would be:

How much resistance should b present on a brand new wire, let’s use the sized wire that is use on the ignition to coil pack as that is what I’m working on now

Then if it is older how much resistance is tolerable?

Another ? I have is if the wiring is good how much voltage should a coilpack produce?

Topic

[Mike]

1) 0.2 ohms or so as measured by a Digital Mulitmeter

2) 1 ohm or more should be considered a problem.

3) 20,000 to 60,000 volts, which varies a lot from manufacturer to manufacturer.

Note: checking resistance in wire like that really only tells you if it’s broken or not because the amount of electricity that the meter runs thru the wire is so small. An example is if you have a battery cable that’s very thick, but 90% of the wire has been chafed thru and only a few strands are still connected. A resistance test will show the same thing on that chafed wire as it would on a good wire because the few strands left are more than enough to fully conduct what the meter is putting out for the test. The correct way to test a wire resistance is with a voltage drop test.

If you want to learn about this kind of stuff top to bottom really easily, get this book from Amazon or somewhere:

[EricTheCarGuy]

Honestly, if it ain’t broke, don’t fix it. As for how much resistance a circuit should have, it’s dependent on the vehicle and the circuit in question. That information is often found in the service manual. Or I should say, the best information on that should be in the service manual.

BTW, don’t bother checking ignition coil resistance. It’s a waste of time unless the coil has completely failed. I’ve obtained this information from ignition coil engineers BTW. The reason is that coils will fail under load. Checking their resistance with a meter does not produce enough current to find a fault.

More info on electrical here.

http://www.ericthecarguy.com/faq/solving-automotive-electrical-problems

[Shad]

So I know that I have at least one coil that produces 20kv…

My first thought is to use that same coil and interchange it between the other 7 connectors, if they all give me the same the wiring is good, right?

Where I see the problem being is if 1 or more, don’t, if that is the case where would I splice into the harness, in general as I understand each vehicle is different.

Where in the service service manual do u think I should look to find the desired voltage output for the coil packs?

[John Hugon]

My first thought is to use that same coil and interchange it between the other 7 connectors, if they all give me the same the wiring is good, right?

Yes

Where I see the problem being is if 1 or more, don’t, if that is the case where would I splice into the harness, in general as I understand each vehicle is different

Watch this video it will explain your system...http://www.youtube.com/watch?v=y4r5OcHN5Lg

Where in the service service manual do u think I should look to find the desired voltage output for the coil packs?

Ford training manual…
Peak Current: 8.5 (AMPS)
Voltage: 35000
Primary Voltage: 14.2
Brand: Motorcraft
Maximum Voltage: 35KV (35000 volts)
Minimum Voltage: 15-20 KV
Primary Ohm Resistance: 0.5
Secondary Ohm Resistance: 5500
Coil Color: Black

[Author]

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