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Until recently, I was convinced that the brown/pink wires were the start circuit.
You knew that they weren't because you had already attached tach wires to them long ago.
You and I were not seeing eye to eye.
Both the 1974 and 1975 diagrams show the starter circuits as brown/pink wires which go all the way from the ignition to the 6v coil wire.
Can they really both be wrong ? Yeah, it appears to be the case, and I've now deleted them off my pc.
I wouldn't be surprised if the red run and white start wires on the ICM are actually the other way round too.
I know that if a 'ballast resistor' goes bad, the engine will not run.
I have no hands on experience with a 'resisted wire' failing, so I simply accepted that the wire could grow old and tired, without really questioning the how and why.
So why were we checking the wires ? Remind me.
Oh yes, going back to page 8, deep within the abyss, there's mention of 12v and 6v (but 12v with the engine running ).
On page 9 there's mention of 3v - 12v fluctuations at the coil with the engine running.
Those comments are more or less the reason that we focused on checking the actual wiring.
We were checking to see if somehow a bare wire, or something, was touching the 6v circuit.
The more we talked, and posted pics, and understood, the more it became obvious that 90% of the ignition wiring was factory, and unmolested by anyone.
The remaining 10% of the wiring was the section that included the 3 cut wires, one of which is still live in run.
That said, back in post 140 on page 10, you went out for a drive and everything was in 100% order. I'd forgotten all about that.
We're kinda back to square one with the ''vacuum advance'' issue, for want of a better description.
We mustn't forget that we checked HT leads, found them to be faulty, replaced them, and fixed a problem.
That bit was easy because each HT lead was tested on its own, and was not part of an overall system whilst being tested.
What a coincidence !!!???
Based on that, we realized that anything was possible, and that we would check for other coincidences and basically check anything and everything.
We found one fault in the wiring, and that was the cut red/yellow diagonal wire which had exposed wires.
What's the chances 12v was escaping from that exposed section and somehow entering the other wires, through their casing, and causing interference ?
We don't know for sure.
When you get a chance, please run your engine and measure the coil + voltage. (MM+ to coil +, and MM- to block.) (Don't make any changes.)
Let's see if it still fluctuates between 3v and 12v. (Probably yes. )
That leaves one other thing that has been repeatedly mentioned. The battery. It is virtually dead and needs to be replaced.
Could the battery be causing our problem ? Maybe. Maybe not. But it needs to be replaced. Period.
Next up is replace the battery, tested first to ensure it reads 12.6v when cold, at the shop.
When the new battery is installed, then check the voltage at the coil + again in the same manner as mentioned earlier.
If the voltage is still fluctuating 3v to 12v then it wouldn't hurt to find and measure the ohms on the resistor wire. It certainly doesn't hurt to check it, and maybe use the book's guidelines for checking which you posted up in a few posts ago, as well as checking just the wire if possible.
That's 3 tests and 1 new battery (and maybe a new resistor wire ?) to rule out the electrical circuit.
If nothing is fixed in those tests then we need to revisit the coil and pickup.
It's a real shame that the Accel 8140 was binned before we could try it again.
I'm going to google something, make another coffee, and then come back with a lot less waffle.
The first, I typed 'Go Seahawks!' followed by the word 'abyss'.
I knew it !
My swollen right ear is caused by 'GoSeahawks!itous' 'if venturing into the abyss between pages 8 and 18'.
I didn't scroll down to see what happens between pages 1 and 8.
The second google search was your 3 coils, 8140, FD471 and FD 476 because I remembered reading things that caught my eye last time I looked.
The 8140 is the only one that advertises its primary resistance, which is 1.4 ohms, and we know that coil was 100% ok.
That sent me back into the abyss to check the coil fittings coz we've never addressed them, and post 159 on page 11 stood out.
Please go and read it and clarify exactly where you measured 2 ohms. (Yes, the FD471 fitted should read 1.4 ohms between the coil + and - terminals, which you verified.)
I'm sure you recall, the boot on one of the HT leads was not fitted correctly, and that was part of a previous problem, subsequently fixed.
Please look closely at the coil terminal attachments(boots?). Any sh$t in there ? Tight fit ? Anything suspect ?
It took us +/- 11 pages to determine EXACTLY what ignition system you have.
It took us the remaining +/- 10 pages to determine that our wiring diagrams are not accurate.
We actually got the answer we're looking for back on page 9 already, but didn't register it due to being sidetracked by everything else.
Forget the small tests mentioned in the last 1-2 posts and simply fit a new battery, tested at 12.6v cold, and fire up your engine.
I reread the posts on page 9. I’m a bit dense sometimes (proven more than once). You’ll have to explain exactly what you’re seeing that explains anything.
The last time I tried starting the engine (after installing the Echlin magnetic pick-up) it wouldn’t run. Read post 167 on page 12. Fast forward to today and nothing has changed except disconnecting and reconnecting several plugs for electrical tests. Why do you expect it to run? 🤔
Page 9 mentioned the 2.1v - 13.2v fluctuating readings, and 12.26v at the battery.
Those are the two tell tale signs, and the first one could be as a result of the second one.
There's no mention of the battery being recharged between then, page 9, and post 140 on page 10 when the engine ran 100% fine. Do you remember charging it at that time ?
Between post 140 on page 10, and post 167 on page 12, it looks like the only thing you changed was the 3 wire connections out of the dizzy, and the stator.
I didn't realize that it hadn't/couldn't run since then. F$$k !
Can you jump the Ranchero battery, from the later model Super duty with its engine running ? (We don't want to abuse a brand new battery.)
If it starts, great, if it doesn't, put the known working stator back in and try starting again.
Once it's able to start, you can fit a new battery.
Your 12.26v battery has weakened cells, camouflaged by recharging, and the sick battery puts out insufficient volts. Maybe only 13.2v as seen in post 167 on page 12, instead of 14+ volts.
You could measure the Superduty voltages before and after you start it, and compare it to the Ranchero, if you want.
Your 12.26v battery has weakened cells, camouflaged by recharging, and the sick battery puts out insufficient volts. Maybe only 13.2v as seen in post 167 on page 12, instead of 14+ volts.
You could measure the Superduty voltages before and after you start it, and compare it to the Ranchero, if you want.
Does this post make sense ?
Everything you wrote makes sense. I haven’t reported when I have it on the automatic charger but it has been, on and off. Yesterday when I was walking by the battery measured 12.3 V cold and untouched for at least 48 hours. However, I don’t believe the battery is the cause of the problem.
The Bronco thread pointed us to the stator. We went through 2 before the engine suddenly ran well, then it just as suddenly and mysteriously reverted back to timing that was “not in step” with what it was set at for initial and at the same time would not accept vac advance. Phasing” if you will. Weak ignition.
It’s then I finally realized I was alternately and seemingly randomly getting 6v (nominally) at the coil in Run. That’s what started down the path of chasing wires to accomplish a few of things: 1) confirm their integrity, 2) understand the wiring and ultimately, 3) find the source of the 6v fault.
So far we’ve accomplished #1, on the wires I’ve physically seen and the condition of the factory harness in the rest of the related circuits. There has been progress on #2 and #3 remains elusive pending #2.
One of the many weird things is that I’ve never seen anything but 12v again throughout the system during all the testing. 6v has not “randomly” appeared again.
That all said here’s my attack plan, in order:
1) take voltage readings at the ICM wires (pink, yellow/blue dot that connects to ICM red (as I recall without looking), the yellow wire (that connects to the white ICM wire (or red if I’m not remembering correctly). I’m also planning on checking at the two plugs I’ve posted a couple of pics of, but you’ve never commented on. They have the yellow/blue and yellow wires as well as a yellow/pink and the larger black/white wire that was cut on top of the engine. I’m hopeful and on the lookout for the resistance wire, too.
These tests are intended to lead to thoroughly understanding the wiring.
2) When the time is right, try starting the engine with the current Echlin stator. I don’t know why it wouldn’t before. My only theory right now is since this stator is the highest resistance of the 3 that have been swapped in, and it ran with the other 2 (and one of them during the brief time the engine ran with vac advance) is that the spark is always weak because of 12v vs 6v “phasing”. That’s as best as I can describe it; I think the concept comes across. My other guess right now is since what’s happening at the coil is directly connected to what’s going on at the ICM, the “bad” 12v is coming through the yellow/blue wire feeding the ICM, when that wire should be 6v in Run (and 0v in Start if my theory is correct).
The tests in #1 will lead to something. Exactly what remains to be seen. I’m hoping to get into this later today.
Any and all comments are welcome, from “you’re full of “$h*t” to “what a genius”. I’m definitely not going to see the latter, maybe the former? LOL
Funnily enough, I’m very pleased that you are going to follow and measure voltage along each circuit.
I’ve wanted you do that for a while now, but wrote it off when you recently stated that you want this all finished sooner rather than later.
Take a pen and paper with you and draw each circuit (Start and Run) noting the actual colors and voltages. At least then you’ll have a 100% accurate wiring diagram.
Hopefully the resistor wire has a different texture to the normal wires and thus can be identified quickly and easily.
Measuring 12.3v at each section will be just as informative as measuring 12.6v, so for this project, a new battery is not required.
I didn’t comment on the two plug pictures you posted because I didn’t have a context within which to 100% know what they were and where they went.
I recognized the colors from our chats, but because they are not in the 1974 + 1975 diagrams, I couldn’t make any comment with 100% certainty.
The factory wiring has way too many plugs and splices and crap for my liking.
My truck had the same crap until I did a 100% rewire and installed several new fuse boxes to facilitate dedicated circuits.
I didn’t spend much time measuring volts/ohms in detail on my initial crap Motorcraft system, but I did spend a ton of time on the modern dizzy/coil combo and later HEI system.
But I’ve just remembered something, although it’s vague, and that is the 1.4 ohm resistor wire, combined with the 1.4 ohm coil resistance, produces +/- 3 ohms to the ignition circuit, and it’s the total ohms, with the engine running, which produces 6v. (I think !)
I’d replace the battery before doing running engine measurements.
The battery is f$$ked. We know that for a fact. It needs to be replaced, for the 110th time of saying so. Why keep a known faulty item in the electrical circuit ?
LOL, I wasn’t convinced that a new battery would be THE solution, but I know it will eliminate any unknowns. (E.G. Maybe the 3v – 12v fluctuations.)
The 12v to 6v to 12v readings might be something as silly as a fault in the keyed ignition barrel. (12v still being provided even after the key returns to run.)
I don’t think your stage 2 plan will take too long.
It’s a real shame that we cannot 100% trust the stators, but as you say, one of them worked, and no, your current one is not an Echlin one.
That was the one that cost $20 or whatever more than the Napa/Standard one you got.
In the near future, you will find the actual fault, and when you do, and correct it, everything you have learned thus far will fall into place like a completed jigsaw puzzle.
LOL, you’re not full of *******, and for sure, best of luck.
Here’s a sketch of the ignition wiring. All the open wires go into a wiring harness, but not necessarily into the same harness. The next step is getting Run and Start voltage readings at critical areas.
I made a big discovery while doing the voltage tests:
At Coil, ICM Connected
Red/green wire, disconnected, 11.91
Coil - (negative) stud, red/green wire disconnected from + stud, 0v
Coil + stud, red/green wire connected, 5.95v
Across both studs, all wires connected, 4.36v
Weird! There’s the voltage we’re looking for but why? As in, what changed? I know I’ve checked the red/green at the coil both disconnected and connected at the stud and seen only nominal 12v a dozen times.
The ICM. It’s been unplugged and replugged and unplugged a few times and left unplugged for extended periods while chasing wiring and doing voltage tests at the ICM plug terminals. Does having it plugged in have an effect on the voltage at the coil? The answer YES.
I unplugged the ICM and ran the identical tests. The different readings are bold underlined:
At Coil, ICM Disconnected
Red/green wire, disconnected, 11.89v
Coil - stud, red/green wire disconnected, 0v
Coil + stud, red/green wire connected, 11.89v
Across both studs, all wires connected, 0v
Someone needs to explain this to me. Apparently the ICM adds resistance to the circuit?? I never gave it a thought while checking voltages before. It may or apparently (?) may not have been connected. Pure chance.
Anyway knowing I had 6v at the coil I attempted to start and ran into the same obstacles that stopped me: extreme rough running, misfiring badly, lots of throttle action to keep running. I made a few incremental advance adjustments without much impact before running out of time.
I know I’ll get it running with some time to reestablish initial advance (I estimated today by dizzy position) and possibly changing out the stator (NAPA/Echlin) since it’s always run rough on this one.
The first question is once it’s running will it be “fixed” and run with vac advance? I don’t know why it would be at this point but I can’t explain why it did, briefly once, either.
The second question is when can I get to it? The answer to that is sometime hopefully this week. More to come…
So what you're saying is, we just spent 12 pages looking for a problem which didn't exist in the first place.
Testing the ignition system with the ICM disconnected is like trying to test a rear light bulb with the battery disconnected.
The coil has a built in resistance of 1.4 ohms required for the ignition components to work together, whether it's a 12v or 6v system.
Reading the ignition wire detached from the coil will always produce 12v.
The 1.4 ohm resistor wire is required to make the entire ignition system 6v.
Removing the ICM plugs in effect took away the 1.4 ohm resisted circuit thus creating the 12v reading. (Note that the coil is grounded to the resisted ICM circuit, not the 12v chassis circuit.)
In effect you have two resisted circuits. Remove either one and you'll read 12v.
I just wanted to let you two guys know that this posting put me into a deep-sleep before my wife.
4-years ago i was chasing gremlins just like SeaHawk on my '77 Ford pickup.
The issue was the engine would cough back through the carb, and also would backfire out the exhaust.
I could not get out the driveway without protest. Hmmmm
Like SeaHawk, I fiddled with everything I could think of and even purchased a new Holley carb which didn't change a thing. Dang.
Finally, I gave in and called the tow company to haul my pickup to the Auto Electric Shop.
We never do win all battles, and sometimes swallow our pride. USA did not win in Vietnam.
Years ago, or decades back, automobiles had a Voltage Regulator with points which corrode.
Dumb me, through all of my fiddling I completely forgot about the remote mount Regulator !!!
Anyway, the local expert at the Auto Electric shop called me and said my pickup is ready to be picked up and bring a check for $300.
Guess what !! my whole problem all along was a bad Voltage Regulator. Doncha-Know.
Recently, since August of 2020, I have been assaulting a '78 Ford Van "do-over" of sorts.
This van was driven daily for 8-years until retired in 2002 because of purchase of a '95 GMC Suburban powered by a 6.5 Turbo Diesel, which we drove for 15-years until purchasing a newer Suburban in 2017. The 2007 Chevy 2500 series 4x4 Suburban has the 6.0L engine w/ tow package. I Like it !!!
In the meantime, on occasion, I feel obligated to fire up and drive the Ford Van for grins.
Truthfully, each time was a Disaster, and so so disappointing, because no matter what I did, the D*mn thing would let me down. All attempts were a NO-GO.
Lately, I have been getting bold and driving the van 6-miles into town as Shake-down runs.
Believe me, each trip has been a big disappointment.
I have been considering renaming myself to "Harvey Wall-Banger" hahahaha
Seems like of all the gremlins I have snuffed since August 2020, I am not Done yet.
On one of my recent risky trips into town, my engine ran decent until i am in town, and the dang thing began acting as if i were running rich. Hmm, what the heck !!
So, when i get home, with engine running, I pull the float level plug from my Holley, and gas spews out in a gusher. Oh heavenly dayz. I shut off engine and pull the primary float bowl, and began removing the screws which hold the float (center mount float) to check for debris in needle and seat.
Guess what !!! D*mned if the float is half full of fuel. no-kidding. ( I still think like a juvenile kid ).
You guessed it, I spent the following evening scrounging the net for a replacement Float.
I first checked all local parts houses, and they no longer keep Holley floats in stock like the old days.
I wound up ordering a float from our local O'Reillys auto parts store.
Next trek into town, and yes, you "know" I've got my fingers crossed for good luck. ( a fairy tale ).
The engine is running pretty well and I am smiling big until I am in town and climb into the van for a re-start and the starter seems Sluggish. !!!! OMG, here we go again.
OK, get home now, and braking with left foot and operating throttle with my right foot. so depressing.
Suddenly, the 'Light' comes on !! Check voltage with engine running dummy. So's I fire up the engine and break out my el-cheapo Harbor Freight red $5 multi-tester and I'm getting 12.2v. Hmm
I do the same check, engine off: 12.12v Hmmm
Why on earth hadn't I thought to check charging output on the voltage regulator ? mush-head.
Very simple: engines today have internal regulators.
Dec. 6, I pickup a new Standard ignition at O'Reilly's and go home and install in my Van.
After that, I fire it up, and sit there for 5-mins waiting for the engine to warm up enough to idle.
Nope, no hand throttle. I'm running a 4160 Holley model 3310 manual choke carb I bought new in 1993 when installing the 385 series 429. Darn tootin I love the 429 engine, never over-heats.
Back to the task: engine is running at an idle, and i jump out and quickly hook HF multi-tester to the batter, and my new refurb (O'Reillys) alternator is pumping out 14.6 volts. Woooopie
I needed this small token of luck to boost my sanity, and was most welcome by the width of my smile.
The sanity boost was welcome because the day before, I failed in my attempt to pull the steering wheel on my '46 ****** cj2a project puzzle. (another one of those orphans that show up).
I am stoked because the "club" puller for steering wheels just arrived from the last victim, and it was my turn to use it. Before exercising the puller, I very so happily used an old snake-oil trick to make the job go easier, yep. I drug and drug my torch set (med tanks) out to my 'yard-art' ****** and put heat from the red-wrench down into the hollow steering column to make it expand. Upon cooling, the steering wheel should be 'loosened' somewhat for easy removal (pulling).
I am superstitious, so if once was good, repeat as before, and enjoy "twice" being nice. Stay on track with me here, I actually applied the Torch to the column 3-times and the last cooling was when I had ran into town in my trusty little '09 Honda CR-V scooter mobile. (she cow-trails like a dream).
That was the trip in to pick up the new Voltage Regulator for my Van.
Back to the ****** steering wheel pulling:
I never did get the wheel removed and spent a long evening ever so patiently and so carefully attempting to remove the POS wheel. Yep, it is a POS because of 80-years of being sun-baked.
The puller base is not against the metal hub of the wheel but against the composite plastic of the wheel.
I knew the composite would fail before the hub would release from the steering shaft. It did fail.
My other fail was the threads on the column shaft. I couldn't see that the threads were rusted away on the shaft, and put the puller onto the assembly and tightened the puller. Next came a few obligatory blows with my 8-lb maul. Next, loosed puller and back off nut further for more puling, and tighthen puller and repeat blows with maul. I go through 6 gyrations of this only to discover the threads are stripped, and i was just backing off a loose 'collar' nut. Oh Heavenly Dayz are here again.
My only choice now to remove the wheel is to break out Dremel.
Dremel has high speed burr bits which will make quick work of carving it's way through composite.
Next, I spend an hour doing surgery on removing enough material on the dash-side of the composite to basically remove the center hub portion of the wheel composite to reveal the steel hub ans spokes.
Now I am getting somewhere, and broke out a long drift punch. I beat on the punch against where the spokes are welded to the hub time in and time again. No Luck or budgie of hub on shaft.
I feel like i've been shafted. Ok, small torque wrench, no torque. Big torque wrench, big torque.
So, i goes to the shop for a larger and heavier drift, being an old king-pin from a '57 Chev pickup. haha
I beat on the spokes again, and only after putting heat on the steel hub, 3 separate times while beating.
About the time I feel like I have Steam exiting my ears, the wheel popped OFF !!! Yeaay and Hoooray.
Please check Voltage Regulator, and if that doesn't fix it, good LUCK.
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Unfortunately nothing is going to happen today. Tomorrow soonest and I’ll post back.
