How's it going? I have a 1987 Bronco 5.0 EFI. I'm getting no spark coming out of the coil. It's a new coil. What happened was I went to Autozone for a new belt. When I got home I turned off the Bronco and went into the house to get my tools to do the belt. I decided to move the Bronco to a better spot and when I got in it would crank but it wouldn't fire up. I could hear the fuel pumps working so it wasn't that and I could smell fuel too. So I pulled the wire from the coil to the distributer and checked it for spark. Nothing. So I went back to Autozone and bought a new coil and a test light. I put in the new coil and I still wasn't getting any spark. I checked in the Haynes book and put the test light from the tach side of the coil to the positive side of the battery and had a rapid flashing light while cranking. According to the Haynes book that meant the secondary circuit in the coil is bad. So I took the new coil back to Autozone and they tested it and said the secondary circuit was bad and they didn't have any more in stock. This was a cheap'o' coil by the way. It was only $18. So I got a refund and went over to NAPA. I bought a better quality coil for $55. I put that on I still didn't have any spark. By this time I had to go to work. I work nights. The other thing I was thinking is that the steel block that the mounting screws go through maybe serves as a ground? The mounting plate for it bolts right to the engine. I haven't gotten a chance to sand and clean up the mounting plate yet but does it sound like that could be the problem? <!--IBF.ATTACHMENT_84724-->

 

Have you got battery voltage at the primary (input) side of the coil? The problem doesn't sound like its at the coil at all but somewhere in front of the coil in the electrical system. I could be wrong but its the direction I'd check first. You should have the same voltage (minus a portion of a volt perhaps) at the primary side of the coil as you do at the battery terminals. If not, the problem is further up the line in the electronics.

 

yeah that's what I was thinking. So I was checking the blue/white wire coming out of the positive side of the coil. It was cut intentionally by the previous owner. and the noise connector with a blue/white wire was also cut. Coming from the ICM the blue/white wire (that originally went to the noise connector) was connected to the wire that had connected the positive side of the coil at one time. It looked to me that the the positive connection and the noise connector were completely bypassed. This apparently never caused any problems before because it ran fine. I'm wondering though if the fusible link at the end of all this blue/white wire mess happens to be burned out. I don't know where that fusible link is though.

 

If you have the Haynes manual you should be able to follow it through the wiring diagrams. Can't find my Haynes at the moment or I'd list it here. I agree though that NOT having the positive side of the coil connected is an issue. If the truck was running before and this condition existed, there was some sort of backfeed of power to the coil somehow. Its the only explanation for the truck still running. Fusible links are simple enough to check and replace. Just make certain you replace a dead one with one of the correct amperage rating as the original.

 

I'll bet your ignition module is bad. It is bolted to the side of the dizzy. You can take it off and have napa check it for free. Thats about the only component in the ignition system that would just stop working all of a sudden.

 

Check if all the wires in the starter engine are plugged, sometimes they become loose or just get d/c.