I just tested the coil it checks out good. I replaced the Ignition Control Module . Still no spark from the coil. What els can i test?

two little post on the coil 16.8 oms to 20.3 oms

one little post on the coil to the big post on the coil 3.56 oms

 

Come on anyone got anything for me to check or even an idea of what it could be.

 

Do those trucks have a condenser?

Did the coil test good on a scope or just yes/no spark?

I thought your problem was a stall while running - now no spark at all?

I have changed the pickup coil in the distrib before and found it was a bad wire in the harness near a connector - all green from corrosion, I'm up north, salt - but this was also on an old plow truck - mid 80's.

And as far a sspecs - ohms etc - you would know more than me if you have a book.

 

Yea thx for a reply. Yes you are right it was stall while running but now it will not turn over at all. I don't believe these trucks have condenser but i could be wrong. Were would the condenser be at? I don't think it has anything to do with the dist because i am getting no spark form the coil.

 

On a point setup the primary winding of the coil is charged on the positive terminal and the points, as they close, ground that winding, collapsing the coil which sends 20,000volt thru the secondary winding and out thru the plug wires and spark plugs. The condenser takes the fiery zap out of the grounding of the primary coil and keeps the points from frying themselves.

On electronic ignition, the rotor in the distrib passes by the pickup coil, and the hall effect triggers the ign mod to collapase the coil. I have put an ohm meter on the orange? wire that comes out of the pickup coil in the diz and the meter, set on millivolts of dc, will flutter but what the reading should be???? And will a bad one still read a bit? Do they go bad that often? This i don't know. I was chasing a corroded wire and, like you, had to start changin' stuff.

The condenser should be right on the side of the coil and within a few inches of where the pos terminal attaches to the coil. There is a spade terminal hanging there and the condenser itself looks like a lipstick sized piece with one wire coming out the end. Very high ohms, I think.

So, not being a know-it-all now, but yes the diz does make the coil fire.

I wish I was closer, with a small amount of moderately cool beer, I'm positive I could steer you in the wrong direction LOL!

But seriously, I'm just throwin' in my 2c, I wish you the best. My corroded wire was a plow truck that just has to run dammit and I don't have the time/money to waste trackin' it down.... too.

 

I re-read your last post and want to know "won't turn over... " means no starter? Or won't fire at all?

To test the coil "backyard style" - disconnect wiring to the coil, apply 12v pos to the pos side of the coil.
Take a piece of wire and make the connection from the neg side of the coil to ground, BUT stay clear of the coil wire coming out the top ( or have your buddy hold it LOL ) cuz it's a gonna zap ya! It should be a bright blue spark every time you tap that neg wire to ground. Should jump a 1/4 gap easily and not be orange at all.

 

Got no spark at all. ill test it that way i just tested the oms on the coil.

 

Look at the connectors too. If that truck uses a "c" shaped black plastic connector that slides onto the top of the coil, it's a pretty poor design and the connectors get mis-aligned and the wires going into the crimps get frayed etc.

Start with the basics too. Check the plug going to the duraspark box -ign mod and make sure there is a 12v+ when the ign is turned on. One wire is 12pos during run but, it is a resistance wire and the other is 12pos during crank but, no resistance wire so it gets a full 12v from the battery. If I remember right that plug going into the ign mod has just two wires - one red and one white - run and crank - which one which ??? The other is orange, blue, purple??? A haynes/chilton book w schematics will help there. And I only point you in this direction as my wife drives an old Bronco ll during the winter and the key switch is bad - you can crank until the battery is dead and no start because the switch never makes the ignition connection. The starter is spinning away , the motor is turning over just fine but no juice to the ignition. So she has learned to give it a burst of crank and then try again and then again..... and after 2-5 times it lights up just fine. Not real cool when it's -10 but it's just a beater.

 

i seen yesterday about checking the ground on the coil how do i go by doing that?

 

ok when testing the coil should i have power on both sides of the coil with the key on?

 

If you are testing the wires that go to the coil, I know one should have 12v pos.

If you are testing just the coil, disconnect it, then apply 12v pos to the pos terminal and then intermittently ground the other terminal to produce a spark. Hook a good spark plug directly to the coil wire on top.

Or just grab a coil out of something that runs and swap em.

I shouldn't even have started giving advice as I am going on a little bit older info. I own a 99 superduty and a 96 diesel so neither one is close to the setup you have. But.... coils are coils.
Years ago I fixed my bosses kids honda motorcycle. My boss told me that one thing for sure the coil is good.... I hung a coil and condenser from a volkswagon on the front of the frame, set the points with a light bulb with a piece of wire soldered to it and vrooom....
Took the tank off and the old coil had plasticy wax ooozzing out. No.... the coil wasn't good. The kid rode it like that till he wrecked it.

 

i am testing the wires that go to the coil i really thank you for the help since no one els will ever respond to my post. Shows how much help they are.