No power going to the ignition coil

Tiny
NPOTGIETER
  • MEMBER
  • 1989 FORD BRONCO
  • 5.0L
  • V8
  • 4WD
  • AUTOMATIC
  • 105,000 MILES
Over the past few months my truck has been stuttering going up hills just before it downshifts, so I decided to change the distributor cap, rotor, spark plugs and wires. Once everything was finished and put back together I took it for about a ten mile drive and it drove better than I could've imagined, lots of power and engine ran and idled smooth. The next morning I had to make a run into town, car started quickly and idled just as it did the day prior. Less than a mile down the road the engine, out of nowhere, suddenly quit on me. It wasn't a slow sputtering death, more like an immediate one and I coasted off the road. At present the car will crank but not turn over, so I've begun with the process of elimination and replaced all the likely suspects; ignition coil, entire engine module, pick-up module, ignition relay and distributor. I also replaced the alternator because there were wire coming from it that went to the starter solenoid to the battery that were completely fried, unknown if that is a result or cause of this. What remains the issue is that there is absolutely no power going to the ignition coil and therefore none to the spark plugs as well, wires leading to and from are completely dead, but it cranks. So with all of that being said, I'm trying to determine, not only is happening, but also if all of this is somewhat directly or indirectly related to me changing the spark plugs etc. I'm guessing that it could be a grounded wire, bad ignition, or faulty ECM, or something else that I just haven't thought to check. Please, if you could shed some light on this'd if you have any ideas on how to test some of these parts without spending money to replace them, I would greatly appreciate it. Thanks.
Friday, May 3rd, 2019 AT 7:27 AM

5 Replies

Tiny
SCGRANTURISMO
  • MECHANIC
  • 4,897 POSTS
Hello again,

So the thick wire going from the starter solenoid to the negative battery terminal is melted. Is this correct?

Thanks,
Alex
2CarPros
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Friday, May 3rd, 2019 AT 7:45 AM
Tiny
NPOTGIETER
  • MEMBER
  • 3 POSTS
Thank you for your response. I’ve attached an image of the burnt plug. The picture shows the plug located on the top of the alternator. Apparently the wires from this plug go to the starter solenoid and then over to the battery. The wires from the solenoid to the battery are fine and I did replace both the alternator and the plug.
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Friday, May 3rd, 2019 AT 8:12 AM
Tiny
SCGRANTURISMO
  • MECHANIC
  • 4,897 POSTS
Hello,

I have included in the diagrams down below the wiring diagrams for your vehicle's starting and charging systems. The problem here is I see no wire from the alternator to the starter. This could describe why the connector and wire is melted.

Thanks,
Alex
2CarPros
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Sunday, May 5th, 2019 AT 1:34 AM
Tiny
NPOTGIETER
  • MEMBER
  • 3 POSTS
Thank you again for your help with my car issues. I actually found the problem yesterday with the help of someone who knows a lot more about the electrical system than myself. What we found was that a wire coming from a fusible link into the ignition module on the distributor had burned up. It had failed at a pin connector between the two and was a bear to even identify it because of how small it was. I doubt that I would've ever found that on my own and just goes to show how insidious these electrical problems can be. So in the end I replaced spark plugs, wires, distributor (ignition module and pick-up module), ignition coil, alternator and new plug to replace the burned up one and countless hours of pulling things apart and putting them back together, all for one little wire that failed and would've cost me nothing and a few minutes to repair. However, I probably replaced a lot of parts that needed replacing and I know so much more about my vehicle than I did before, so I guess that it all evened out. Thanks again.
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Sunday, May 5th, 2019 AT 7:14 AM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 48,363 POSTS
Use 2CarPros anytime, we are here to help. Please tell a friend.
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Tuesday, May 7th, 2019 AT 6:56 PM

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