Hi everyone, this is my first day on the site. I will soon be getting the truck I have wanted since I was 14 years old, my Dad's 78 250 camper special. It has been sitting for awhile, and when I asked my Dad why, he said it keeps burning up "computers" and won't run. I took a look at what he was talking about, there is some electrical part on the top of the left front fender cover, forward of the hood brackets. It has melted a plastic like substance out of it that pooled downsteam. It looks like is connected to the wiring harness with 2 plugs. He has replaced it 3 times already.

What is this thing, and how can I fix it???????

Russ

 

It's a spark amplifier box or an ignition trigger. It sees the hall effect trigger inside the distributor and then fires the coil. It is no more a computer than a stereo amplifier is. I'm sure other people will come along with more trouble shooting tips but it sounds to me like either the box it getting too much voltage or too much heat. Try replacing the box and mounting it to the fender with some washers spacing it away from the inner fender -- like a standoff. This allows air to circulate around it for better cooling. You could also try moving it to the other side of the hood hinge mount bulge so it can act as a heat shield between the box and the engine.

Do a search on duraspark ignition or duraspark conversion to see if you can find a post with a wiring diagram. I think the box getts full voltage. He might also be getting the wrong box from the parts store. The boxes are identified by the color of the grommet the wires come out of. I think that for most of our trucks the grommet should be blue.

Good luck and let us know what you find.

 

That's good advice on the spacers - the module should have 1/4" space between it and the fender. Try to find a Motorcraft module, I purchased mine at O'Reilly Auto Parts. If you can't find one locally, I've seen them listed online at Auto Parts Giant.

Hope this helps. I know about wanting Dad's truck, the '77 was my Dad's.

 

Check to make sure the coil is good and the resistor wire from the ignition switch to the coil + terminal has not been bypassed. A repair manual has a good diagnostic process for your ignition system. If you have low resistance anywhere in the primary circuit it can cause too much current to flow and melt the coil or module.

Get a Motorcraft module and put 5/16" hex nuts under it to allow cooling air under it. You can often find good Motorcraft modules in the salvage yard, -just have them tested (free at most parts stores). Aftermarket ignition modules other than Motorcraft often fail in 6-12 months.

 

Here is an illustration of the system.

http://www.clubfte.com/users/mil1ion...ssIgnition.JPG

Now, here is a pic of what you are asking about.

If you look real close bottom right,you can see the gap under the box.

Btw, the common everyday term is "Ignition Module or Modulator"

 

How often and when have you used them (aftermarket)?

 

Thanks for all the info everyone. And for the "part" vocabulary. I think my Dad is one of those guys that gets the cheapest part, no matter who makes it. That will not be the case henceforth for this truck, it's going to have a great life.Russ

 

I saw many of the aftermarket DS units fail when I was wrenching and in the years afterward. I also had several fail in my vehicles, many brands, sometimes right before my eyes. One minute they were fine and the next the idle would drop and then no power. To this day I have never had a Motorcraft unit fail and that is all I run nowadays (KOW). I have also recently been using spacers under the modules after I read a Ford TSB on the subject. Many of the original Motorcraft units in vehicles may have been replaced via the "shotgun" method of troubleshooting. Ford did the original design work on the module and I have a feeling that they know some things that the other knock-off suppliers don't. I have been thru the design process myself on many electronic devices and industrial machines. There are lots of things that we found out in the design process that a copycat would not know. The aftermarket suppliers do not have the liabilities that the OEM's do either. I can't say as much about the Ford TFI ignition modules that were mounted on the distributor, -that was just dumb. To much heat conducted from the engine. They seem to function fine when mounted on a heatsink on the fender tho.

Just recently I went thru two Borg-Warner fuel pressure regulators on a vehicle. One only lasted about 15 minutes. A Motorcraft unit is still functioning after about a year.

 

Now that's an interesting statement. Are you refering to moving the TFI module from the distributor to the firewall? Or were you talking about a duraspark module? I've got one of those just dumb TFI ignition modules on my 86 E150. The truck has been a real pita since I've owned it. I think I've been thru 2 or3 modules and maybe ready for #4. The system could use any help it can get and moving the module sounds like a plan to me. Will it work? Ford sure named it right only in my book the F doesn't stand for film.

 

The TFI module works fine when moved to the fender. The DS unit was always mounted on the fender. Check to see if there is some sort of kit to move the module with connectors etc. Check with the guys in your 86 forum. Those trucks used the TFI module.

 

Thanks Torque! I'll check it out for sure.

 

Just let me point out that I am not against using Motorcraft parts because I do. I just don't feel or know that I have purchased a better product just because I paid more for it.

I would just like to see something real to grab onto and not base any conclusion on hearsay, opinions or conjecture.

 

Hi Everyone!,

I'm the guy who had Ignition Module questions a few weeks ago. I'm finally picking up Dad's 78 F250 C.S. that keeps burning modules up. I was wondering if there is an upgrade (petronix or something) that can be used instead of the module. Any help would be great!!

Russ

 

The pertronix module would replace the points, not the module. Jacobs had an ignition system that would replace the module. There are also other aftermarket ignition systems, but the stock one was decently reliable. If you cannot keep a stock box in your truck, you may have as much trouble with aftermarket units. See if you can fix the stock unit first to make it last. Try a name brand module first.

 

If you keep going through modules (of this type), you need to look elsewhere for a problem(s).
Improper grounding, faulty installation, power supply problem, etc.

Heat was/is usually the culprit that got to these early modules.

I agree also (for what that's worth) that upgrading 'the module' certainly isn't where I'd start if you're having module problems already. You can get into more than a few bucks and not solve your problem.
Upgrade the entire ignition system (not just part of it) later if you want after the problem has been cured.