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66-96 Ford Broncos - Early & Full Size
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regarrr

No Spark!?!

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How's it going? I have what seems to be a similar problem with DHPT99 with my spark. I'm getting nothing 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?

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The pickup coil in the Dizz is a very common problem, if you no luck with the new coil I would suggest focusing your attention to there. It definately wont hurt anything to clean up that bracket, the cleaner the connection the better.

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The pickup coil in the Dizz is a very common problem, if you no luck with the new coil I would suggest focusing your attention to there. It definately wont hurt anything to clean up that bracket, the cleaner the connection the better.

 

Whats the pickup coil on the Dizz?

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Hmmm how can I describe it, are you familiar with the inside of a distributor? Take the cap off and look inside? If not I'll try and find a pic

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Hmmm how can I describe it, are you familiar with the inside of a distributor? Take the cap off and look inside? If not I'll try and find a pic

 

Yeah I had it opened up a couple months ago. I remember pretty well what it looked like. I'm at work and the Bronco is at home so I won't be able to look right away.

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I just ran outside and took a picture of one, this is off my '84 351 but it will give you the basic idea. Its the blue gizmo there.

 

 

Pickupcoil.jpg

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I just ran outside and took a picture of one, this is off my '84 351 but it will give you the basic idea. Its the blue gizmo there.

 

 

Pickupcoil.jpg

 

Sorry I didn't get back sooner. My internet went out. ok. so before I saw the photo, I went and replaced the distributer cap and rotor. It was cheap and looked like it could be replaced so I did that. While I was at the parts store a guy told me to put a plug directly into the wire from the coil and check for spark. I did that and got no spark. So does that leave me with some obscure wiring problem? I really hope not. There is a rubber piece on a wire that goes into the TACH side of the coil connection. It was wrapped in electrical tape. I have no idea what it does.

 

I have something similar in the distributer. It's brown and wraps about a third the way around the inside of the housing. What does it do?

 

Man, and I was supposed to be putting on a new Flowmaster today. It tends to feel like a love hate relationship.

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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.

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Wow. I'm really scratching my head now. I traced the white/blue wire all the way back to where it starts. Saw no fusible link whatsoever, the diagram shows a fusible link. So I decided to check the continuity, at least that would tell me if it was broken somewhere. It is fine. Where does the coil get it's power from? Does it come out of the ICM? maybe it's one of the two green/yellow wires that go into the + side? If so, those wires come from the ICM. Hmmmm...

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Joe, you have me scratching my head a bit here, why would you give a link to early duraspark ignition systems? I fail to see the relevance, maybe its just me?

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86 they went to efi for 5.0 engines

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I have a wiring diagram here but cant post it. how do you post a PDF document?

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Ill try this

 

wiringdiagram87.jpg

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I have that same diagram. Fuse link D is the one I was looking for when I was tracing the white/blue wire. But I checked the whole length of the wire and found no fuse link. Like I said I checked the wire for continuity and it was good from start to finish.

 

So last night around dark I decided (not sure if it was a good idea) to put the white/blue wire from the + side of the coil directly to the + side of the battery. Turned the key and she fired right up. So at least I know the problem is no juice to the coil. I really doubt it would be safe to leave it that way so I still wanna figure out how to re-wire it the way it is intended to be.

 

I've gotta take a break on it though. Wife want's to go on a date... I'll be back at it tomorrow though.

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Yesterday I poked my better eye on a branch, and dropped my glasses and they broke. So even though I have an older pair of lenses, it is difficult for me to read smaller print. Therefore I can not check my comment by any authority before I post, so if I screw up, please forgive me.

 

I seem to recall that the circuit to the + side of the coil gets its power from the ignition switch, I think in some systems it first it has to go through the NSS neutral safety switch/shift lever position sensor. What has me confused though is that you stated that when you tested the coil with a test light, that you were getting blinking. I think that would indicate that you are getting power, and that the pickup coil inside the distributor is working.

 

At any rate haynes and chiltons do a good job of walking one through the system, and it looks like you have it pretty well nailed down. Good Job!

 

Regarding fusible links, I think that they can be replaced with inline fuses. I also think that they are typically within the wiring harness near the battery, and in the newer cars, near the power distribution box. The color of the link depicts the amperage it is designed to carry.

post-9476-1225638397_thumb.jpg

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i hate it when previous owners monkey with the vehicle wiring of major things like ignition:) The 89 i got for parts someone wired a toggle switch into the igntion to ground the coil out and kill the spark.

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I posted it so we can all talk and see the same thing, the other way we were only able to read what you read and had no real idea what you were talking about. Now we can see without a doubt. When I look at the wire I see that it branches off from the coil to the tfi modile and to the noise capacitor thingy. The other end of the wire goes to the fusable link. When you trace it i'm wondering if you follow it and end up at those other places. Have you probed the wire to see if it has power before the coil? I am thinking where the butcher cut the wire and twisted it together is causing a crappy connection. I would start at the hack job and put proper connections in place. If all else fails you can wire it to a keyed power source til you can fix it properly. Dont wire it to a constant hot wire, it should be keyed.

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the noise cap is not technically needed so dont worry about it for now. it is there to reduce interference between your radio and ignition system. The ignition system will create a buzz or hum in your stereo(maybe).

 

im at a loss finding you a picture of a fusible link but here is one style.

 

k798274562yfh.jpg

 

the other style is basically just a wire and it may have a little rubber tag on it. these are basically wires designed to melt or burn up if overloaded. Id say the one for this system is 30-45amp rating maybe, but thats just a guess.

 

this is the best pic i could find of the other style

opk_25.jpg

 

it may just look like someone used a butt crimp connector and added this on.

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kind of small but this is supposed to be a ford style fusible link

 

MOT-60364.jpg

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here are some pictures i just took. the first two pics are of an 89 5.0. because of the loom i wasnt able to trace the wires for you. The second pic is at the starter relay to show you a fusible link wire(the green wire in my fingers you can see at the eyelet there is a black plastic block). the third pic is of my 85. i think that big block is another style fusible link ford used on older stuff(but im not sure).

 

 

PB020001.jpg

 

PB020002.jpg

 

PB020003.jpg

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Yesterday I poked my better eye on a branch, and dropped my glasses and they broke. So even though I have an older pair of lenses, it is difficult for me to read smaller print. Therefore I can not check my comment by any authority before I post, so if I screw up, please forgive me.

 

I seem to recall that the circuit to the + side of the coil gets its power from the ignition switch, I think in some systems it first it has to go through the NSS neutral safety switch/shift lever position sensor. What has me confused though is that you stated that when you tested the coil with a test light, that you were getting blinking. I think that would indicate that you are getting power, and that the pickup coil inside the distributor is working.

 

At any rate haynes and chiltons do a good job of walking one through the system, and it looks like you have it pretty well nailed down. Good Job!

 

Regarding fusible links, I think that they can be replaced with inline fuses. I also think that they are typically within the wiring harness near the battery, and in the newer cars, near the power distribution box. The color of the link depicts the amperage it is designed to carry.

post-9476-1225638397_thumb.jpg

 

Come to think of it, I did read something about coil juice coming from the ignition switch. Sorry to hear about your eye and glasses. I think when I tested the coil with a test light, I did it wrong. You know how sometimes when you test something, It's better to not know what's supposed to happen? Well I knew that the TACH side of the coil to the negative battery post was supposed to give me a rapid flash and it didn't. So when I tried TACH side to battery positive and saw the flash, I thought that was good. Sorry for the confusion, I screwed that up.

 

I did find 3 fusible links in the wire harnesses over the driver side wheel well. They look like little 1 inch long rubber blocks around a wire. From the points of the white/blue wire that I could check (from the coil to the terminal mounted on my air filter box) for continuity, it was good. I didn't find a fusible link though. I wonder if it was removed at some point. I hope not. I'd rather melt a fusible link than something expensive.

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here are some pictures i just took. the first two pics are of an 89 5.0. because of the loom i wasnt able to trace the wires for you. The second pic is at the starter relay to show you a fusible link wire(the green wire in my fingers you can see at the eyelet there is a black plastic block). the third pic is of my 85. i think that big block is another style fusible link ford used on older stuff(but im not sure).

 

 

Thanks. I forgot that fusible links could be wire shape too. I found a few rubber block ones like in your third picture. When I traced that White/blue wire (it's about 3 feet long) there was about an 8" section that I couldn't see because it had such a nice wrap around it and I didn't want to tear it up. I felt it for a block fuse link and didn't feel one but it's probably got one that is wire style. Thanks for the pictures. The white/blue wire has continuity all through there though so I don't think I need to worry about the fuse link anymore. Thanks again.

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you have continuity but do you have power? Should have power with the key on. Check at the farthest end that you can access and probe your test light into the wire.

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