I posted a problem earlier here, but I can find it.
so indulge me again please.
I've swapped a (I believe 82 351w) into my 1991 F150 302 4x4 supercab.
I keep frying the modules, truck starts fine, runs great, but after about an hour maybe the module melts, some one suggested voltage was too low, but i've checked it and its charging at 13.32 v plus or minus, is the voltage too high, I thought that I'd missed a resistor wire to the module, but it was the ballast resistor to the coil, which according to the book I have, is in the passenger compartment, so I've never touched it.
However its been 8.5 years since I started this project, so my memory's a little fuzzy, there is a white wire that goes to the module( along with a red in the same plug) which is cut off, I can't see where the wire is from(according to the diagram I have its from the ignition switch and is used only in the start position. could this being unhooked cause the modules to heat up to the point of melting down? I just ran the truck for 5 min and the metal casing of the module is heating up. I understand some heat is likely but don't want to damage this module.
Sorry for being so long winded and thanks

 

Here's your original thread: https://www.ford-trucks.com/forums/1...ch-module.html

Can't help much beyond that, sorry.

 

Here is a wiring diagram for your ignition system"

courtesy of oldfuelinjection.com

The start signal is the red/light blue wire. Having it unhooked should not cause a problem as you described.

 

A little more info on this swap is warranted. That '82 motor would have been carburated while the original 5.0 in your truck was EFI and because none of the EFI parts from a 5.0 will fit a 5.8 you would have had to install a 5.8 intake and distributor to make this work with EFI.. unless you converted the truck to carb at the same time. So what are the details of this swap, what have you changed from the original setup?

 

Personally, I like to bake my ignition modules.

 

Served with rice or potatoes?

 

Ok here goes, I removed the 5.0 from the 91, I installed a 82? 351 W, with carb, I installed a programmer for the E4OD tranny, I used the orginal fuel pumps by installing a fuel pressure regulator, I have a Duraspark II igition module and distributor. Engine starts fine runs without missing a beat until the Duraspark II module overheats and melts. Which can take 20 to 40 min.Yes there are none of the EFI parts on the engine. And to the best of my knowledge none of the computer stuff is being used either except the fuel pump is one for one second like it was orginally
What I need to know is this" which wire coming from the ignition switch is the resistor wire or is there one? The book I have shows the Duraspark system, however the updated pages at the end of the book do not show any information on the ignition switch , not even the diagram provided earlier in this thread, so I ohmed it out, in run, the black and green wire closed, Red & green wire closed, Gray & yellow wire closed. In start black & pink wire closed, red &blue wire closed. With the hot wires to the switch being yellow. When I say closed I mean contacts in the igntion switch have closed making contact with the main supply wire the yellow. In the diagram provided by "Rrla2005" earlier I see a 22K ohm resistor in the system called "ignition supression resistor" Does this take the place of the "Ballast resistor" in the older ignition systems? Could I hook up the coil to use this resistor when running but to full voltage when starting. You might need to see a diagram of a Duraspark II system to see what I'm talking about.
And thanks for any and all ideas. I just need this to run for 2.5 months until I get my new truck. Ford F350.

 

According to this idagram, the NEG isde of the coil has the resistor in line, correct? The The EEC is the module which sits behind the grill on the drivers side of the firewall.
Is the resistor used with the instrument cluster?

 

The 22k ohm resistor is for the IDM signal to the computer (PCM). Now that I know you have completely dismantled the EFI and ignition system I cannot help you. I am not that familiar with the older Duraspark II ignition.

 

The answer to your question in bold is no, that does not replace the older ignition ballast resistor.

 

This thread will probably answer your questions:https://www.ford-trucks.com/forums/5...on-module.html

 

I think I have this working now, ran truck over to car wash yesterday and checked module, it was engine compartment temp, ran another 30 min in driveway, looks good. Biggest problem with this sort of stuff is lack of really good wiring diagrams, containing the information needed, The Haynes manual I have for the 91, doesn't contain a diagram for it.
Tomorrow will be the big test, I'll need truck to get to the hospital for test, I have an extra module just in case.
Thanks for all the help!!

 

You need a 1.3 ohm ballast resistor in the red (Hot) wire to the coil.
If you look at the diagrams this is bypassed while cranking.
The DSII module does not see resistance at any point.