Notices
1973 - 1979 F-100 & Larger F-Series Trucks Discuss the Dentsides Ford Truck
Sponsored by:
Sponsored by: Moser

Ignition module trouble

Thread Tools
 
Search this Thread
 
Old Jun 15, 2013 | 09:07 PM
  #1  
1979 300i6's Avatar
1979 300i6
Thread Starter
|
Senior User
Joined: Jan 2013
Posts: 303
Likes: 0
Ignition module trouble

Ok my starter has stuck into start postion when you turn the key to start it Automatically starts without turning it and the starter Continues to Engage, but when I Disconnect the red and white wire from the Ignition module the starter works normally but of course does not start. I hope this makes sense if it don't just ask thanks
 
Reply
Old Jun 15, 2013 | 10:13 PM
  #2  
fmc400's Avatar
fmc400
MSEE
Joined: Apr 2004
Posts: 10,386
Likes: 35
From: Austin, TX
Club FTE Gold Member
I can't understand what you're saying. You're saying the starter itself is stuck into "start position"; what does that mean? The starter is turning on its own? Under what conditions? It starts without turning it; what is "it"? The key? Does start mean the motor actually fires up? What lead you to disconnect the ignition module?

Let's try this again with you stating the scenario very clearly and concisely without making anyone work to figure out what you're trying to say.
 
Reply
Old Jun 15, 2013 | 10:40 PM
  #3  
wilcam47's Avatar
wilcam47
Senior User
Joined: Feb 2013
Posts: 266
Likes: 0
From: Idaho
Can it just be your ignition switch?
 
Reply
Old Jun 15, 2013 | 10:59 PM
  #4  
1979 300i6's Avatar
1979 300i6
Thread Starter
|
Senior User
Joined: Jan 2013
Posts: 303
Likes: 0
Ok gotcha, you know how on the Ignition switch you have Accessory, Off, run, start, ok the starter will turn over when it's turned to RUN withought ever turning the key to start, also the starter will NOT stop turning once the engine starts, what has lead me to the ingition module is that it died on me and would not start up agine so I figured it was my cheap china Ignition module had went bad so I replaced it and that's when my problems stated above Begined, so I figured something in the Ignition module was causing the starter to engage when the key was on RUN postion, so with Trial and error I found out that the starter Performs normally when the red and white plug in is Disconnected.
 
Reply
Old Jun 16, 2013 | 07:43 AM
  #5  
montana_highboy's Avatar
montana_highboy
Post Fiend
Joined: Apr 2008
Posts: 8,261
Likes: 15
From: Big Sky Country
Faulty ignition switch.
 
Reply
Old Jun 16, 2013 | 09:06 AM
  #6  
fmc400's Avatar
fmc400
MSEE
Joined: Apr 2004
Posts: 10,386
Likes: 35
From: Austin, TX
Club FTE Gold Member
Thanks for the clarification. In this case, I think your ignition module has an internal short between the RED and WHITE wires. The hot-in-START signal that feeds the starter solenoid is the same hot-in-START signal that runs to the ignition module. If there is such a short and you apply hot-in-RUN power to the ignition module, it would make sense that the starter prematurely engages. The fact that disconnecting the ignition module from the hot-in-RUN and hot-in-START circuits alleviates the issue further points to a faulty ignition module. I would say the ignition switch was the culprit if the problem was independent of the ignition module being connected, but that doesn't appear to be the case here. According to your description, the problem follows this specific ignition module. If it were your switch, the problem would happen with the old ignition module too.

If you have a spare module, swap it out and see if the problem persists. You shouldn't run the cheap foreign-made reverse-engineered modules from O'Reilly's, Auto Zone, etc. ONLY use a Motorcraft module; while they are much more expensive, they are the only truly suitable replacement. So in this instance I would say replace your module anyway, because you shouldn't run the one you're running in the first place.
 
Reply
Old Jun 16, 2013 | 09:16 AM
  #7  
montana_highboy's Avatar
montana_highboy
Post Fiend
Joined: Apr 2008
Posts: 8,261
Likes: 15
From: Big Sky Country
Maybe I read the OP's post the wrong way, but I understood it to say the problem persisted with both old and new ignition modules.
 
Reply
Old Jun 16, 2013 | 08:19 PM
  #8  
1979 300i6's Avatar
1979 300i6
Thread Starter
|
Senior User
Joined: Jan 2013
Posts: 303
Likes: 0
Ok I fixed the problem with the starter kicking in on the "Run" postion by putting a new Ignition module on it, but when I tried to start it, it would Hit (run) for a second but once I let off the key it would die, I repeated this several times with the same results, any thoughts?
 
Reply
FTE Stories

Ford Trucks for Ford Truck Enthusiasts

story-0

Top 10 Fords at 2026 Carlisle Ford Nationals

 Joe Kucinski
story-1

3 Best / 3 Worst Parts of Modern Ford Ownership

 Brett Foote
story-2

10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches

 Pouria Savadkouei
story-3

Every 2026 Ford Engine Explained

 Brett Foote
story-4

10 Ugly Ford Trucks That We Still Kinda Love

 Joe Kucinski
story-5

10 Things Every Truck Owner NEEDS (2026 Edition)

 Michael S. Palmer
story-6

Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath

 Verdad Gallardo
story-7

Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer

 Joe Kucinski
story-8

2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)

 Brett Foote
story-9

Top 10 Ford Truck Tragedies

 Joe Kucinski
Old Jun 16, 2013 | 08:21 PM
  #9  
fmc400's Avatar
fmc400
MSEE
Joined: Apr 2004
Posts: 10,386
Likes: 35
From: Austin, TX
Club FTE Gold Member
Now it sounds like an issue with the ignition switch. You can easily pull the ignition switch and check all positions of the switch using a multimeter checking for continuity. Are you going to do this?
 
Reply
Old Jun 16, 2013 | 08:27 PM
  #10  
1979 300i6's Avatar
1979 300i6
Thread Starter
|
Senior User
Joined: Jan 2013
Posts: 303
Likes: 0
Yes I am, thanks for your helpful advice, I'll report back on the results
 
Reply
Old Jun 17, 2013 | 12:07 AM
  #11  
montana_highboy's Avatar
montana_highboy
Post Fiend
Joined: Apr 2008
Posts: 8,261
Likes: 15
From: Big Sky Country
You were told ignition switch in post number 3 and 5....fmc likes to over analyze stuff, it's his nature, but sometimes it's an easy quick fix that is the best fix.
 
Reply
Old Jun 17, 2013 | 07:52 AM
  #12  
fmc400's Avatar
fmc400
MSEE
Joined: Apr 2004
Posts: 10,386
Likes: 35
From: Austin, TX
Club FTE Gold Member
Originally Posted by montana_highboy
You were told ignition switch in post number 3 and 5....fmc likes to over analyze stuff, it's his nature, but sometimes it's an easy quick fix that is the best fix.
In this particular case, I'm confident the ignition module was responsible for the first issue. That doesn't mean the ignition switch wasn't also bad all along, but there was no way to know that initially (other than lucky guesses). If the ignition switch was solely responsible for the original behavior as it was described, I don't see how disconnecting the power lead of the ignition module could alleviate the original issue. There is no way to explain the original issue based on the ignition switch alone (the switch has no sense of what's connected downstream). Several folks suggested replacing the ignition switch, but no one offered an explanation as to how it could cause the specific behavior as it was described in the original post.

If not for the statement that disconnecting the power lead of the ignition module made the behavior go away, then I would agree that the ignition switch was solely responsible for the first issue. If people don't agree with me, then I'm open to hearing how the behavior as it was described could be explained by a bad ignition switch alone (I could just be missing something). Keep in mind that the original issue as it was described went away after replacing the ignition module, and only appeared (based on my interpretation) with the installation of the suspect ignition module. My understanding is that the motivation for replacing the ignition module in the first place was that the original was completely dead and the truck would not start. With a second ignition module, the odd starting issue appeared. With a third ignition module, the odd starting issue disappeared, but a second, seemingly unrelated issue appeared (that was likely there all along). It sounds like the ignition switch was bad all along, but it's clear the second ignition module was bad too - and there would have been no way to spot the former until the latter was taken out of the picture. And even now I'm not telling him to replace it yet; I'm telling him to ohm it out in case this still isn't the problem.

The second, equally likely possibility is that I completely misunderstood what this guy is saying from the get-go (he seemed to clear it up in his follow-up post though).
 
Reply
Old Jun 17, 2013 | 08:16 AM
  #13  
gfw1985's Avatar
gfw1985
Cranky Old Guy
Joined: Mar 2008
Posts: 3,562
Likes: 6
From: Raphine, Virginia
Originally Posted by 1979 300i6
Ok I fixed the problem with the starter kicking in on the "Run" postion by putting a new Ignition module on it, but when I tried to start it, it would Hit (run) for a second but once I let off the key it would die, I repeated this several times with the same results, any thoughts?
In this situation, I have found module's with the red and white wires swapped at the plug. Make sure the wires match the pins. If swapped, it will give that result.
 
Reply
Old Jun 17, 2013 | 09:35 AM
  #14  
fmc400's Avatar
fmc400
MSEE
Joined: Apr 2004
Posts: 10,386
Likes: 35
From: Austin, TX
Club FTE Gold Member
Originally Posted by gfw1985
In this situation, I have found module's with the red and white wires swapped at the plug. Make sure the wires match the pins. If swapped, it will give that result.
That's a great suggestion. I will point out that one needs to be careful; in most cases the colors should look swapped; it's when the colors match that one needs to be concerned. Coming from the truck, RED with a BLUE stripe is hot-in-START, and WHITE is hot-in-RUN. Early Duraspark II modules matched; RED was the hot-in-START input and WHITE was the hot-in-RUN input.

However, these days, almost all modules (even Motorcraft) are manufactured backwards: RED is hot-in-START and WHITE is hot-in-RUN. However, the orientation of the plug remains correct. That means the module will plug in and work, but RED will be going to WHITE, and vice-versa. If you see the opposite (meaning RED to RED and WHITE to WHITE), there's a chance they're actually swapped (as odd as that sounds), but if it's an aftermarket foreign module, it's anybody's guess. It's yet another reason to stick with a Motorcraft module - the colors are swapped, but at least one knows they're swapped and the modules are consistently backwards. With knock-off modules, sometimes even the colors in the 4-conductor plug are mismatched.
 
Reply
Old Jun 18, 2013 | 09:27 PM
  #15  
1979 300i6's Avatar
1979 300i6
Thread Starter
|
Senior User
Joined: Jan 2013
Posts: 303
Likes: 0
This was the problem the wires were backwards
 
Reply



All times are GMT -5. The time now is 01:30 AM.

story-0
Top 10 Fords at 2026 Carlisle Ford Nationals

Slideshow: Top 10 Fords at 2026 Ford Nationals

By Joe Kucinski | 2026-06-09 11:10:08


VIEW MORE
story-1
3 Best / 3 Worst Parts of Modern Ford Ownership

Based on years of owning multiple modern Ford products.

By Brett Foote | 2026-06-09 10:53:36


VIEW MORE
story-2
10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches

SPONSORED: From muddy boots to rain-soaked cargo, these upgrades address some of the most common frustrations Ford truck owners face every day.

By Pouria Savadkouei | 2026-06-08 18:50:34


VIEW MORE
story-3
Every 2026 Ford Engine Explained

Here's everything you need to know about every Ford engine available for the 2026 model year.

By Brett Foote | 2026-06-05 12:58:01


VIEW MORE
story-4
10 Ugly Ford Trucks That We Still Kinda Love

Slideshow: 10 ugly Ford trucks that we still kinda love.

By Joe Kucinski | 2026-06-03 09:51:16


VIEW MORE
story-5
10 Things Every Truck Owner NEEDS (2026 Edition)

Slideshow: the best gifts for dads & grads

By Michael S. Palmer | 2026-06-03 15:43:58


VIEW MORE
story-6
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath

Slideshow: Called the Fortress, the 850-horsepower pickup combines Raptor underpinnings with military-inspired features, survival equipment, and a starting price of $285,000.

By Verdad Gallardo | 2026-06-03 11:38:36


VIEW MORE
story-7
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer

Slideshow: 10 most expensive Ford trucks ever sold on Bring a Trailer.

By Joe Kucinski | 2026-05-27 16:24:34


VIEW MORE
story-8
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)

Here's everything that has changed for the latest model year.

By Brett Foote | 2026-05-27 16:17:28


VIEW MORE
story-9
Top 10 Ford Truck Tragedies

Slideshow: Top 10 Ford truck tragedies.

By Joe Kucinski | 2026-05-18 19:34:33


VIEW MORE