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Coil gets HOT and engine cuts out. 1984 F250

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Starliner

Re: Coil gets HOT and engine cuts out. 1984 F250

Well, this should be interesting, I plan to adjust the ignition switch today. It was new when I installed it 2 weeks ago. I do not remember seeing any locking pin, (didn't look), so my fear is that I just bolted it on and sheared the pin when I took it out of drive. If it is sheared off in there, maybe that would be my issue with high running voltage at the coil + side, (14.3V).
I guess I will find out soon enough. If it IS in fact sheared, I guess I will try a magnet to get it out if possible.

JOE
1984 F250 HD 2wd auto w/air,
351W, 2bbl, Dana 60 3.73, no EEC

Gary Lewis

Re: Coil gets HOT and engine cuts out. 1984 F250

Administrator

Take it off and shake it. The pin may fall out.

If you look at the schematic there appear to be three separate switches inside the ignition switch module. The one on the left brings in the starter. And both switches on the right are used for the ignition.

I've noticed on other trucks that those switches aren't perfectly aligned internally. On an old switch in cold weather the Start switch will open as you roll the key back from Start to Run, but one of the other switches won't make so the accessories like the clock and radio don't come on.

I'm thinking that your left switch is opening up so the starter drops out, but the right switch is staying connected so the resistance wire is bypassed.

Gary, AKA "Gary fellow": Profile

Dad's: '81 F150 Ranger XLT 4x4: Down for restomod: Full-roller "stroked 351M" w/Trick Flow heads & intake, EEC-V SEFI/E4OD/3.50 gears w/Kevlar clutches
Blue: 2015 F150 Platinum 4x4 SuperCrew wearing Blue Jeans & sporting a 3.5L EB & Max Tow
Big Blue: 1985 F250HD 4x4: 460/ZF5/3.55's, D60 w/Ox locker & 10.25 Sterling/Trutrac, Blue Top & Borgeson, & EEC-V MAF/SEFI

Starliner

Re: Coil gets HOT and engine cuts out. 1984 F250

Makes sense that the resistor wire is getting bypassed.
This is great. The sad part is that I had read your switch adjustment instructions BEFORE installing it, then, for whatever reason, did it my way anyway. Comprehension is an important part of reading.
Thanks.

JOE
1984 F250 HD 2wd auto w/air,
351W, 2bbl, Dana 60 3.73, no EEC

ArdWrknTrk

Re: Coil gets HOT and engine cuts out. 1984 F250

Administrator

Ohm it out.
You'll know right away.

Jim,
Lil'Red is a '87 F250 HD, 4.10's, 1356 4x4, Zf-5, 3G, PMGR, Saginaw PS, desmogged with a Holley 80508 and Performer intake.
Too much other stuff to mention.

Starliner

Re: Coil gets HOT and engine cuts out. 1984 F250

Ok, since I am lazy, I try the easiest thing first.
Last night she ran flawlessly. When I checked the coil it wasnt hot.

The only thing I did yesterday was to sand down all battery and cable connections.
I am getting running voltage of 10.71 at the positive coil when running.
I made sure that the voltage held throughout the "travel" of the ON key position and it did.

As a matter of priorities, now that she is running like a clock, I dont have to 2-foot it when driving. With the idle nice and low I am noticing front brake grab, both sides. After sitting for 10 years I am not surprised.
So i will end this thread, and will post any coil updated here but will otherwise end this discussion on my side along with many thanks.

BRAKES!

JOE
1984 F250 HD 2wd auto w/air,
351W, 2bbl, Dana 60 3.73, no EEC

Gary Lewis

Re: Coil gets HOT and engine cuts out. 1984 F250

Administrator

Well, that's an even easier solution. Well done!

Gary, AKA "Gary fellow": Profile

Starliner

Re: Coil gets HOT and engine cuts out. 1984 F250

UPDATE: Well, maybe this will help someone in the future, and hopefully this is really fixed this time.
The problem seems to be that the ON position to the key switch has 2 clicks before going to start and both clicks show different voltage to the coil. So even after adjusting it using Gary's detailed instructions, the coil was still intermittently heating up and eventually quitting on me due to too much constant voltage, (I think). The voltage wasnt always getting bypassed to the resistor wire. So my workaround solution was to adjust the ignition switch by using a volt meter. Negative to ground, positive lead to the + wire at the coil. I placed the volt meter against the windshield so I could watch the voltage at various positions to determine the best position for the ignition switch.

This is not the ideal setup, the key cylinder itself or the slide rod has some kind of hang up but I think I have it. If not, I will post.

JOE
1984 F250 HD 2wd auto w/air,
351W, 2bbl, Dana 60 3.73, no EEC

ArdWrknTrk

Re: Coil gets HOT and engine cuts out. 1984 F250

Administrator

Do you have tilt wheel?
If pushing the turn signal stalk forward unlatches it, it may be a sign of a failing actuator, because you have a new switch and it isn't supposed to be like that.

Look at any of the EVTM diagrams.
There are only Accy, Lock, Run and Start.

Jim,
Lil'Red is a '87 F250 HD, 4.10's, 1356 4x4, Zf-5, 3G, PMGR, Saginaw PS, desmogged with a Holley 80508 and Performer intake.
Too much other stuff to mention.

Starliner

Re: Coil gets HOT and engine cuts out. 1984 F250

It is not a tilt wheel. Definitely the 2 clicks in the ON position is odd. To double check I swapped back my stock switch and that confirmed it was a good ignition switch. A 35 y/o electrical component, those were better times.

JOE
1984 F250 HD 2wd auto w/air,
351W, 2bbl, Dana 60 3.73, no EEC

ArdWrknTrk

Re: Coil gets HOT and engine cuts out. 1984 F250

Administrator

That would make me think the switches are both good and there's something going on with the column or actuator rod.

With the switch that you have out of the truck, is there a fifth detent if you manipulate it?

Jim,
Lil'Red is a '87 F250 HD, 4.10's, 1356 4x4, Zf-5, 3G, PMGR, Saginaw PS, desmogged with a Holley 80508 and Performer intake.
Too much other stuff to mention.

Gary Lewis

Re: Coil gets HOT and engine cuts out. 1984 F250

Administrator

In reply to this post by Starliner

Starliner - You are saying that the old switch does as the new switch does and has two separate positions in On? Just wanting to make sure I understand.

Jim - If you look at the schematic you can see there are multiple wipers. And from my experience it isn't uncommon to find that they make and break at different positions in the rotation. For instance, it is not unusual at all to have the grease set up in the winter so that letting the spring pull the switch back to On just gets the ignition circuit and not the one that powers the radio and other accessories. And to get the accessories on you have to manually rotate the switch farther.

So in this case the switch is coming out of Start on the left wiper so the starter motor is turned off, but not out of Start on the right wiper so the ballast resistor is still being bypassed.

That's very good to know. And, the alignment process doesn't fix that. Just the ingenious testing with the DVM. Well done, Starliner!

Gary, AKA "Gary fellow": Profile

Starliner

Re: Coil gets HOT and engine cuts out. 1984 F250

Necessity is the mother of invention.
Its definitely something with the actuator rod. I tried using electronic cleaner and even cleaned the rod and column with steel wool but it is a mechanical hang up which is preventing a nice healthy return to ON from START.
Thanks.

JOE
1984 F250 HD 2wd auto w/air,
351W, 2bbl, Dana 60 3.73, no EEC

ArdWrknTrk

Re: Coil gets HOT and engine cuts out. 1984 F250

Administrator

That's great investigative work!

Now you know how and why it happens, even if you can't find a fix right away at least you can avoid it happening again.

Jim,
Lil'Red is a '87 F250 HD, 4.10's, 1356 4x4, Zf-5, 3G, PMGR, Saginaw PS, desmogged with a Holley 80508 and Performer intake.
Too much other stuff to mention.

grumpin

Re: Coil gets HOT and engine cuts out. 1984 F250

There’s been many people that did not realize they have a tilt wheel on this era of truck.

Turn signal lever pushes forward. You may well know but thought I’d mention it.

Dane
1986 F250HD SC XLT Lariat 4x4 460 C6-Sold
1992 Bronco XLT 4x4 351W E4OD
1998 GMC Sierra SLE K1500 350 4L60E
Arizona

old55pete

Re: Coil gets HOT and engine cuts out. 1984 F250

In reply to this post by Starliner

Now Im not sure about your 84, and I was thinking that my 86 with tilt has four poshions in the ignition. Before I commented, I went out and checked. Mine has ACC, lock, unlock only then on/ run and start. I also checked my Brick nose and it is the same.

Steve
86 Bronco, XLT, 5.0 EFI, EEC IV, AOD, IFS, limited slip front and rear, 3.08 gears, Tilt steering, factory AC

Starliner

Re: Coil gets HOT and engine cuts out. 1984 F250

Not a tilt when but very interesting info. I think we are zeroing in on things here.
The problem is still there. It quit on me and I had to put my spark box on it to get home.
This is getting old.
I'm wondering if the cold heats up too much being mounted horizontally on top of the engine in front of the carb.
Also, maybe I will get a ballast resistor and put it in line to see if that helps.
Like I said, this is getting old!

JOE
1984 F250 HD 2wd auto w/air,
351W, 2bbl, Dana 60 3.73, no EEC

ArdWrknTrk

Re: Coil gets HOT and engine cuts out. 1984 F250

Administrator

My coil was mounted horizontal from the factory and it was fine for 24 years.
Electrical components wear out, especially when they're being cycled hundreds of times a second.

Has your truck been backfiring at random?
When this happens, does it just stop, or does it get worse and worse until it finally dies?

Jim,
Lil'Red is a '87 F250 HD, 4.10's, 1356 4x4, Zf-5, 3G, PMGR, Saginaw PS, desmogged with a Holley 80508 and Performer intake.
Too much other stuff to mention.

Starliner

Re: Coil gets HOT and engine cuts out. 1984 F250

It just dies and wont restart. I can smell the unburned gas. It is a swapped out coil so the original one was likely fine.
Not likely the problem is downstream of the coil since my emergency starter box gets me home. It is somewhere between the key and the coil.

JOE
1984 F250 HD 2wd auto w/air,
351W, 2bbl, Dana 60 3.73, no EEC

ArdWrknTrk

Re: Coil gets HOT and engine cuts out. 1984 F250

Administrator

If it cuts out clean and then will restart when cold, I respectfully suggest it IS downstream from the coil

These are classic symptoms of a failing DSII module.
The green wire going to the module has to sink the same current that's going through the coil.
The transistor inside really can't take the abuse.

We (somehow) have to find a solution to your balky ignition switch.
But unfortunately I think it's time to replace the module as well.

Jim,
Lil'Red is a '87 F250 HD, 4.10's, 1356 4x4, Zf-5, 3G, PMGR, Saginaw PS, desmogged with a Holley 80508 and Performer intake.
Too much other stuff to mention.

Starliner

Re: Coil gets HOT and engine cuts out. 1984 F250

Ohhhhhh, I hear ya.
I did replace the ICM , but now you have me thinking.

JOE
1984 F250 HD 2wd auto w/air,
351W, 2bbl, Dana 60 3.73, no EEC

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