How do you know if your ignition control module is bad?
 

Hello,
I am new on here and I was hoping to get some advice from you guys. I have a 1973 Ford F-100 that has an electronic ignition from a 1974 Ford F-100. How do I know if the ignition control module is bad, because when I try to start it, it turns over very slow. Sometimes when I try to start it turns over very fast and normally starts. Thanks for any advice in advance.

That's more of a battery and or starter issue.

Welcome to the site btw.

Welcome to the site! I'm new also. When my module went bad my truck wouldnt run at all. I bought a new one at advance auto parts for $21.

I doubt that it's an ignition problem. Like Montana_highboy said, it sounds more like a starter/battery problem.
Have the battery checked to make sure its good. If it is, the next thing to check are the battery cables, in particular the ground cables. Make sure you have a good ground directly to the engine block. Also make sure the cab and frame have good grounds also, this doesn't have anything to do with the starting problem but it will help avoid other pesky electrical problems down the road.
Clean and tighten all of the cable connections.
If there is still a problem, have the starter checked.

Thanks for making the point about the starter/battery. Since I got the truck, I have looked at the starter and it has a big dent in it. Would that affect why it isn't starting? I tried to start it the other day and it turned over ok and it sounded like it wanted to start, but it didn't. I am not sure if it is the battery because I bought it in February.

These old rides only need two things to run; spark & fuel. That's what I like aboutr them over the computer type sensor style rides of the 80's above.
The dent in the starter ; might effect it turning and was prolly cause by someone denting it to clear headers or the likes.
If the ignition module is bad or no contact with a ground cable it wouldn't turn over alick.
Oh;
Also "Welcome Aboard" as well. Best place to have a Ford Truck.

Mitch

I was thinking it might be the spark plugs because today I tried to start it and it was turning over real good and sounded like it wanted to start but it didn't. We checked to see if we were getting gas to the carburetor and it was. It was also getting gas to the engine as well. We checked the spark plug and spark plug wires and it wasn't getting spark, so we went to the auto parts store and got new spark plugs and put them in and then tried to start it and it did the exact same thing it did before, didn't start. I think it is demon posessed.

If you have a test light and a multimeter, there are tests that can be made - here's a link that might help:

https://www.ford-trucks.com/forums/8...-problems.html

Thank you Furyus1, I will check that out. I think that might be the problem!

Thank you everyone else for their very helpful information, y'all all contributed to what might be the main problem.

The three step scenario of a failing DuraSpark ignition module.

1) Module overheats, engine dies. Module cools down, engine re-starts almost at once.

2) Module overheats, engine dies. Module cools down, engine re-starts in an hour or so.

3) Sooner or later, usually sooner, the module overheats, burns out. Now the engine will not re-start.

Since these modules are notorious for failing when they overheat, taking it to an autoparts store to have it tested..usually does not work...because it's cool.

DuraSpark was introduced in 1974 on passenger cars/trucks. 1974: The module is the same for both, but it's 1974 only. 1975 is not the same.

D4AZ12A199C .. Ignition Module (Motorcraft DY157B)

Marked: D4AE-12A199-A1A or A1D, or A2C, or A2D.

So my truck won't turn over if the ignition module is bad, right?

Yes, the engine will crank, but whether it cranks slow or fast has nothing to do with the ignition module.

It may act that way due to a fully charged or low battery.

Replacing the spark plugs has nothing to do with the problem.

If you aren't getting any spark to the wires or plugs, it could be a faulty coil, ignition module, or?

I can tell you this, Ford mechanics once refered to DuraSpark as NeverSpark...because the modules used in 1974 (and 1975) were crap!

I installed the entire wire harness from a 75 truck into my 77 truck and had no spark. Turned out the modules are different so when I installed the 75 module, truck ran fine.
Might be something to check anyway? The grommets are color coded.

1974 is a one year only module: D4AZ12A199C.

1975 is a one year only module: D5AZ12A199C except on some early 1976 Bronco's which use this same module.

1976/79: Most cars/trucks use the same BLUE module (1U2Z12A199A replaced D9VZ12A199A).

1976/79: Some cars/trucks sold new in CA use a different RED module: D7AZ12A199A.

1978/79: Some cars/trucks use a BROWN module: D9AZ12A199C / 1979 LTD/Mercury Grand Marquis sold new in CA use: D9AZ12A199B.

Blue/Red/Brown: Above where the wires feed out of the module, is a colored plastic square.

It stops working. :D

I thank everyone for their help, but I was wondering what the advantage of having electronic ignition over regular ignition?? I found a new distributor for regular ignition at an auto parts store for $41.99. I was thinking about going back to regular ignition, instead of getting a new magnetic pickup (If that is the problem). The guy at the auto parts store told me that a new magnetic pickup is $40. Might as well get a new distributor and go back to regular ignition. Any pointers on what I should do?

Not exactly. Look at numberdummy's post.

Also the modules can fail in weird ways too.

The start and run circuts are wired to the module seperately, so a problem with one may not affect the other. (The engine cranks and cranks and fails to start, but when I let off the key it starts syndrome) or (the engine starts but then stops again when I let off the key)

The Duraspark-I is notoriously problematic. As Numberdummy stated... "Neverspark". Parts are also hard to come by and expencive when you do find them.

The Duraspark-II (Blue Grommet) is considered highly reliable, and a worthwhile upgrade from a points system. Very few components to fail. No dwell to adjust etc... And replacement parts are easy to get, and not all that expencive.

The Duraspark-I and II are not swappable or compatible with each other, so a rewiring would be required to swap them around, or get a harness from a 1976 or newer truck.

So with that said, Points system is better than DS-I but DS-II is better than both of the latter. ;)

Is points less wiring than DS-II? I want to go with the one with the least amount of wiring.

If you look on the back side of the module ( At least on a Dura Spark I ) , look to see if there are two clear spots on the back. If you see Two spots throw it away , it aint no good , move over to the next truck on the U- pullit yard and buy that one . Ed Shaver

81-F-150-Explorer and others: I have a similar problem with our '76 F250 - 460 engine. She usually runs fine (except for guzzling the fuel!) but lately is becoming much harder to start when cold. Yesterday she began running real rough and then quit with a strange "run-on" sound - then dead (with a ton of firewood in the back!!!)

I noticed that during the hard starts over the last weeks in the morning, after a good crank and no start, when I turned the ignition switch off, there was a single cough each time.

Could this simply be a bad ignition switch? Is there a way to bypass the ignition switch so that power gets to the ignition system directly?

Before I begin systematically checking the Duraspark module, coil and distributor, I'd like to eliminate the simple stuff. I will check all the grounds (engine ground strap) due to all the body & frame rust. Are there other ground wires in the ignition system - is the DuraSpark unit grounded through the casing to the body?

Also, is the "Blue Grommet" easy to see on the DuraSpark II module?

Thanks - hope I haven't highjacked this thread...

Points is less wiring, (3) although needs more upkeep and maintenance. Also needs precise adjustments.

DS-II, although it has more wires (6), three of those are between the module and distributor, two is between the module and coil, and/or ignition switch run circut, and one is between the module and "I" terminal on the starter solenoid. The advantage is a cap and rotor, Plugs etc... is a tune up. No adjustments, longer intervals between tune ups, hotter spark. etc...

Not hard at all to wire, especially with a DS-II harness from a donor vehicle. All you need is to hook up three wires. 1976-1986 had DS-II systems, but the earlier the better chance you will find the harness.

But do what you are comfortable with. I'm only giving you suggestions. :)

Unlikely. But not impossible. What it sounds like is the coil colapses and fires (once) when you shut the power to it off at the switch. This is relatively normal. However are you getting spark while cranking? Check the I terminal at the starter solenoid. That is the coil resistor bypass with the ignition switch in the start position. Also check the red wire at the coil in the run position.

No, the DS module is grounded through the distributor base, using a wire. (Black if I recall correctly, away from my manuals)

Very easy to spot. It's the grommet where the wires go into the module. DS-I's can be Red for 1974, green for 1975, etc...
DS-II's can be Blue, Brown etc...

Blue is the most comon and the most simple.

I've owned my '77 for 32 years. I'm on the 3rd module. The first one went after 3 or 4 years and the second one went about a year later.

That's not a problem with the ignition, you are having carburetor issues. Sounds like the choke isn't working properly.

What are you talking about?

Thank you 81-F-150....
I'll attack the problem over the next week or so (the vehicle is on an islated island)

When you say coil resistor "bypass" do you mean there should be 12 volts at the "I" terminal when you crank or should the 12 volts disappear when you turn to start.
No, I got no spark when I grounded a plug against a headbolt. But, I'm not confident there was good contact - must try it again.

Didn't the DSI module have a black grommet in 74?

RED DuraSpark CA only Ignition Module: D7AZ12A199A (Motorcraft DY204) / Obsolete

Fits: All 1977 CA V8 passenger cars // 1978 CA 302 Mustang / Fairmont/Zephyr / Granada/Monarch // 1979 302 CA LTD/Mercury Grand Marquis / Mustang/Capri / Granada/Monarch / Fairmont/Zephyr.

This module was a total POS! The module used on 1977's and on some early 1978's were defective. Ford had them on D99 = National Back Order for THREE months!

It was a FIASCO!

1000's of new and nearly new cars were parked on dealer service lots, because no one was able to get any.

I bought all the used modules I could find locally at wrecking yards, so the customers could get their cars back.

After three months, the modules became available again. The first shipments were also defective!

It took another TWO WEEKS to get modules that worked. It's no wonder that Ford mechanics refered to DuraSpark as NeverSpark!
-------------------------------------------------------------------------------------------------------------------------------
BLUE DuraSpark Ignition Module: 1U2Z12A199AA (Motorcraft DY893) / 1U2Z-12A199-AA replaced D9VZ-12A199-A and D6AZ-12A199-A / Available from Ford.

MSRP: $130.60 // FTE sponsor Y2KFORDPARTS.COM price: $70.52.

Good to know 81-F-150-Explorer, I need to decide what I am gonna do when I get some $$$$$. Thanks for the help.

I know it is jacking but I must answer if I know an answer

Mr. Fixit the sound you heard is commonlly known as dieseling there is nothing real wrong with it happening but it can be hard on parts so you do want to try and figure out what is going on. The most common fixes are new carb floats and choke adjustments make sure your choke is working correctly if not well then there you go and it is always a good time to rebuild your carb.

That was a error on my part, not the first or last.

Red was the crappy module that Bill posted.

It should be 12 volts when you crank the engine at the "I" terminal. The I terminal has no power in any other mode.

The coil's Red/Lt. Green Wire should have 6-8 volts at run.

The Red/Lt. Green wire at the coil and the brown wire at the starter solenloid are tied in together after the ballast resistor in the harness. So the brown wire at the "I" terminal may also have 6-8 volts with the ignition switch in the on position but this is just bleed over from the Red/Lt. Green wire.

Sounds like a plan, make sure you have spark, then I would turn to the carb, as it sounds like you have issues there too.

Yes, all the modules and California specific parts sometimes gets mixed up in my mind. Sorry bout that. California was never really car friendly after 1970.

Alot of experimentation went on in California, at our expence. IMO. The cars here were subjected to EEC-I, EEC-II, EEC-III etc... all very complicated worked half the time, hard to diagnose, crap. Sometimes they would break down before they left the lot. At least by the time EEC-IV came out, Ford worked out most of the kinks. Even the early 80's pickups were plagued by these weird computer systems in this state. Most mechanics don't have a clue how to work on these systems either.

A little update here on our '76 with the 460... checked out the (blue grommet) Duraspark connections and found the correct signal...fast flashing of the test light at the coil. I'm beginning to get the impression this is not an ignition problem but a carb one, as USArmyTaterness says.

I have already converted to a manual choke so that should be OK.

Will check the readings as 81-F-150 suggests at the I terminal + coil and also the float in the carb next time I'm "over there".

Here are some more symptoms. After a hard start with plenty of cranking before she sprang to life (poured some fuel into the carb) she was running perfectly for about 2-3 minutes. Then she died on the road and refused to start. There were two backfires that caused a neighbour to come running out. He thought I had ended it all in dramatic style. Then she started again and ran perfectly.

Could the float be sticking and then opening/filling the bowl?

I've never touched a 4bbl carb... can I open and clean out the float chamber easily? I'll phone NAPA about a new float. Would prefer not to rebuild the carb until winter arrives and I have some time.

Thank you all for your help - you'll get me through this eventually!!!

:-missingt I'm adding this to my sig - too funny...

What kind of carb do you have (Motorcraft, Holley, Edelbrock, etc)?

Furyus1: It's a Motorcraft 4 bbl carb Model 4300 or 4350 I think.
the tag says: D2VE:8620:LA DF G273

it could still be the battery... they can be bad even new... i went through 2 batterys in less than a yr recently on my truck.. reason it was changed the first time was because it was old and wasnt holding a charge anymore... so that 2nd battery worked great for couple months and started having problems again... i was thinking i had a bad grounding problem somewhere that was draining the battery.. turned out id gotten a new battery that had 2 dead cells in it out of 6.. when they checked it back at the store they "tried" to tell me it was a good battery just because it "passed" their draw bench test.... but my hydrometer said other wise... i got another battery and havent had problems since with starting...

that 2nd battery would sometimes have enough juice in it to kick over normally.. other times it wouldnt even try or turned slowly..

personally id change that starter too just because of that big dent.. but thats just me... i dont like seeing big dents in parts that have moving mechanical parts in them...

Here's a diagram I found for the 4350 (I'm assuming the 4300 is similar):
http://www.ifsja.org/tech/fuel/4350.html

There's a bunch of stuff attached to the air horn - might be better to pull it from the truck first before cleaning/rebuild...

Just a thought...