No Spark From Coil

[Fisherleep]

I have been narrowing down a starting problem for the past few weeks and have gotten it to the coil. I have a 75, I bought a good used harness, new coil, new distibutor, ignition module, starter relay, carb. All of the dash compenents are not hooked up but I figured that this would not effect the spark. The engine turns over fine, I am getting 12v out the ingition module, and 12v into the + side of the coil and ~6v into the - side. However I get 12v out of the coil when it is in the key "on" position, with the key to "start" I get 12v also. I have tried multiple ingnition modules b/c I understand they go out quickly. Does anyone know from a schematic or by testing theirs what voltage is suppose to be coming into the coil during these key positions? If the 12v and 6v is correct, what else could be causing the coil to not send the correct voltage to the distributor? What else is the coil dependent upon besides those two (+/-) wires? Thanks.

 

[Wildturkey]

You should have 8 or 9 volts in run position and 12 volts starting on the plus side of the coil and 6 volts coming out on the neg side according to Chiltons manual.What happens when you run a wire from the positive side of the battery to + on the coil?Do you have the correct 75 year module?Colors should be red,blue,white,green,orange,black,and purple.Have you checked the distributor pickup coil also.Hope this helps.

 

[Fisherleep]

I will test what you suggested tomorrow. What is the distributor pick up coil, I am not familiar with this? Anyone else with suggestions?

 

[Fisherleep]

The pickup coil is good

 

[Wildturkey]

Maybe this link will help because it sounds like it's not wired right for a duraspark.You have to have ignition and start going to the module for it to ****** and spark.Duraspark modules are real dependable,at least for me,I have the original on an 78 F-100.I thought it was bad a couple of times but after checking I found loose connections were the problem.Check this link out because he has a TFI coil conversion.http://users3.ev1.net/~bmarr/duraspark_ignition_upgrade.htm

 

[Seabronc]

Ditto on the last post. There are two connectors to check located right next to the Ignition module. Also grounding of the distributor. For grounding of the distributor, use a meter and check from your battery (-) to the ***** that grounds the pickup coil inside the distributor, It should be 0 or darn close. If it isn't check the cable from battery to engine block for bad connections.

The most common symptom of a bad pickup is the truck will start and then as it warms up it will shut off. However, it could be completely dead and I have gotten bad pickups right out of the box.

A diagram of the Duraspark II system is atttached below.

Good luck,

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[Seabronc]

additional info

 

[Seabronc]

additional info

 

[Seabronc]

More info

 

[Seabronc]

Next page

 

[Seabronc]

Yet another page

 

[Guest]

Good post Seabronc!

 

[Guest]

I finally got that SOB running strong. Thanks for everyones info especially yours seabronc that post of pages was full of information. What book was that out of? Thanks again

 

[Fisherleep]

Forgot to log in ^^^^^^^^^^^^^^^

 

[Seabronc]

That was out of the EVTM (Electrical & Vacuum Troubleshooting Manual) for the 1983 Bronco. I don't know if they produced an EVTM for your year truck but the following link is a good source of manuals.

http://www.autobooksbishko.com/products/index.asp

Good luck and glad /emoticons/[email protected] 2x" width="20" height="20" /> you found the problem, exactly what was it.

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