Heres the deal. I have a 77 F250 High Boy. 400 motor. I pulled it out back to work on it the other day. It started and ran fine. I put ne battery cables and a new Solenoid on it. The solenoid was broken so I put the old one back in. This truck has a new distributor,coil,plugs,wires,battery,just about everything. Anyway, now the truck turns over and starts running as long as the starter is spinning. As soon as I let off the key it dies. There is power off the solenoid to all wires but nothing at the coil. My buddy says there is a fuseable link that is possibly blown and the wiring diagram I have says the same thing. Anybody know where that link is or have any better ideas??

Any help would be great !!!!

 

How many small terminals & wires is on the solenoid?

There should be 2.

One for Starting and one for 12 volts ignition during start up.


Here is your igntion system.



The power to the coil comes from the ignition switch.

It is the PINK resistance wire at the back of it.

That's what I think your problem is.


The fusible link is in the harness leading to across the firewall from the solenoid.
Usually that is for main power to the key & fuse box.

Please put the actual topic in the title.

 

I will take a look at it thanks very much.Sorry about the header it was out of frustration.

 

Oh and there is 2 terminals on the front.

 

Remove the two wire harness at the electronic ignition module. The with a voltage meter check the red wire and the white wire for battery voltage when the Key in the ON position. What is the positive battery voltage to these two wires?

It seems like these wires at module do not have voltage when the key is in the ON position.

 

Thanks for the help. I will try these things and post back.

 

Ok. The Red Wire going into the ignition module has power. Now, What wires coming out of the ignition module are supposed to have power? All I have is a test light at the moment. For some reason I checked the coil and now there is power there when there wasnt before. Am I to assume I should replace the ignition module? Maybe it is only working some of the time?

 

The red wire (pin #4) should have positive voltage as should the wire going to coil (pin #1) + or minus battery voltage.
Does the coil have spark now ?

Check for any loose wire connections or cracked wires at the coil and at the distributor.

Here the two test for the coil:
With an Ohms meter, check the for ohms from 7,000 ohms to 13,000 ohms from the red wire (pin #4) to the top of the coil tower.
And check for 1.0 ohms to 2.0 ohms from pin #1 to pin # 6. Here is the pin (socket electrical schematic for the electronic ignition. https://www.ford-trucks.com/user_gal...=94669&width=0.

We can all refer to each wire by Pin # (socket #).

 

Duraspark Ignition Module Wiring

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Some ignition module, have on 2nd harness, either two wires or three wires coming out of silver dura spark ignition module box.

At the ignition module amplified box.
You will fine two (2) harness going into ignition module, there is a four (4) wires (1st harness) and two (2) wires (2nd harness).

At module (1st) harness with four (4) wires, three wires will run to distributor (wire colors: orange, pulple, and black ) and one color green goes to the negative post on coil tower.

At module (2nd) harness is what provides the positive energy to the ignition module and has two (2) wires (wire colors: red and white). One wire gets the power during the Key Start position and the other wire get power when the Key On position.

The positive side "+" of coil housing tower gets power when the KEY is in the ON position and the wire color is red with green stripe. This is a separate three wiring harness. The three wire harness (3rd harness) has a red with green stripe wire which feed positive feed to the positive side of coil when the Key is ON position. The red with white stripe wire plugs into the temperature sending unit. The white with red stripe plugs into the oil sending unit.

The three wires coming out of the distributor housing and plugs into the wiring harness will have three wires with colors: black, orange with yellow stripe, and black with blue stipe.
These wire coming out of distributor housing run directly to the ignition module. The black wire runs to the black wire on ignition module. The orange with yellow stripe runs directly to the orange wire on ignition module. The black with blue stripe runs directly to the blue wire purple wire on ignition module.

The 2nd harness at the ignition module has two wires, red wire and white wire.
The red wire from ignition module should have power when the Key in ON position.
The white wire should have power when Key in Start position.

The 2nd harness (red and white wires) plugs into another harness having red and white wire harness. The colors for some odd reason switch, and the red wire from ignition module goes into the corresponding white wire from other harness, and the white wire from ignition module goes into the corresponding red wire from other harness. It is better to be working on actual two wires (2nd harness) to visualize what is being mentioned and to avoid any confussion.

Power supply to the 2nd harness (red and white wire at ignition module) is supplied from positive side of battery, which supplies the power to the ignition switch. When Key is On position, the power is feed directly from the ignition switch to the red wire coming out of the ignition module. When the Key is in the Start position, the positive power goes to electrical wire, red with blue stripe at the starter relay (aka: starter solenoid). This red and blue stripe wire triggers the starter relay and engages the starter motor, it also supplies positive feed to the brown wire which plugs adjacent to the red with blue stripe wire. This brown wire gets feed positive energy to the white wire coming out of the ignition module. Therefore, the one positive feed red and blue stripe wire, triggers the relay (thus engaging the starter motor) and positive feed the brown wire on starter relay prong which supplies positive feed to the white wire at the (2nd harness) ignition module.

 

These two test will require two persons.
Next test. With key in the START position.
Locate the two wire harness coming out of the ignition module. One wire is red wire and one wire is white. Check for positive feed at the white wire with the KEY in START position. Is there positive feed with the Key in START position in the white wire at the ignition module?

Next test. With key in the ON position.
Locate the two wire harness at the ignition module. One wire is red wire and one wire is white. Check for positive feed at the red wire with the KEY in ON position. Is there positive feed with the KEY in ON position in the red wire at the ignition module?

New Test
You will need to print out the next two links and follow the test on second link using the socket # (pin #) of first link.
Here the wiring for the electronics of ignition module, pickup coil, coil, ignition and etc. Second link is the test of pin # (socket #). post if with results and questions.
https://www.ford-trucks.com/user_gal...d=94669&width=0
https://www.ford-trucks.com/user_gal...d=94668&width=0
Will need a voltage meter and Ohms meter for some test.

Use a note paper to keep track of your test results. Write down what wires have voltage, and what ohms for each test. It will help you in tracking down the problem and when you post back.

Post back if you have any questions.

 

Wow. Thanks for all the info. I did replace the ignition module ( they dont cost much ) but now it doesnt even turn over. I think I had a bad starter or I had it cocked in when I tightened it because the teeth are gone on my flywheel. I mean there are teeth but I think they are half or less of what they used to be. So, my next project is replacing that. The starter kicks out its just not catching.Ive gotten alot of good advise on that also. Thank you very much for replying and I will try all of those tests as soon as I can get the flywheel replaced. Its gonna snow soon and I have NO garage so that is # 1 right now.


Thanks

 

Power Supply to Red Wire and White Wire Coming out of Ignition Module.
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To avoid any confusion if anyone is using this thread. All references made to the red wire and white wire coming out of the ignition module (Dura Spark Igntion).
On the white wire on 2nd harness (red wire and white wire) coming out of the ignition module.
The WHITE wire coming out of the ignition module box should have positive power when the Key is ON position. This white wire at module is directly fed with positivie power from the red/ green stripe wire at the ignition switch.

On RED wire on the 2nd harness (red wire and white wire) coming out of the ignition module.
The RED wire coming out of the ignition module box gets its power from the red / blue stipe wire at the ignition switch when the Key is in START position. When the Key is START postion , this red / blue stripe wire at ignition switch provides power to the red / blue wire at the starter relay (metal prong) and then provides positive power to the brown wire located at the starter relay (aka starter solenoid). This brown wire located at the starter relay plugs into on of the two metal prongs at starter relay. When the red/blue wire get positive feed at starter relay, it also provide power to the adjacent (second prong) and give the brown wire power, thus providing the power all the way to the white wire coming out of the ignition module.

 

Just as an update and for future reference....the whole problem I was having was with the solenoid. I didn't figure this out untill a day or 2 ago but the problem was that the solenoid wasn't grounded well enough. Apparently the original solenoid was grounded good and when I replaced it, even after cleaning all the bolts and everything else, the ground wasn't good enough. All I did was run a jumper from the solenoid base to the negative terminal on the battery and she popped right off. Well, atleast I got a whole lotta new updates on my truck. ha ha ha.


Thanks again for everyones help. Could not have done it without you guys

Tommy

 

Good to hear your trucks running again,
Never heard of a grounded solenoid not making the truck start. Learn something new every day. Good work Tommyrs33.

 

Well, I figured it out when I bought a new solenoid and just hooked it up without mounting it. Nothing happened. When I hooked to the one on the fender, the starter would spin but not engage. That me think a little. I figured out that the base of the solenoid is how it grounds itself. If ya think about it, if the solenoid was on the starter there would be a ground going to it. On the fender both the big main wires are power.One is taking power(from the battery)and one is giving power(to the starter).So the mouting bracket is the ground. Apparently the ground wasnt good enough so it wasnt throwing enough power to the starter to kick the gear out. The battery was shot also but I was using a jump box. Now with the new battery and that ground wire she pops no problem!!


Once again--thank you everyone for all the info

Tommy