Duraspark problem
Cargo Master
Joined: Mar 2008
Posts: 2,573
Likes: 207
From: Washington
The pink with double green labelled "resistor do not cut" is under the hood, coming from the main bundle out of the firewall on the left side. Mine looked brown, it being dark out didn't help, I had to clean it up to see the color and that's when I noticed the writing. It's not very long, I'll measure tomorrow. That part of my harness was wrapped up pretty good. It'll likely be in the thickest portion because of the bulky factory splice.
https://www.ford-trucks.com/forums/1...l#post17690723
I thought you had it all unwrapped. It's just been one of those unsolved mysteries on this forum.
Jim
Moderator
Joined: Nov 2007
Posts: 22,415
Likes: 92
From: Denver Metro Area, CO
The TFI ignition was used only on certain engines (6-banger & 302 V8) but the wiring harness contained wiring for both the DS2 & TFI systems, allowing one harness for all trucks built on the production line.
Cargo Master
Joined: Mar 2008
Posts: 2,573
Likes: 207
From: Washington
No Spark troubleshooting info:
The round coil and the square coil use a different coil wire as the coil end is different. Most new wire kits have both in the box to cover more truck years. Make sure the coil wire fits correctly. I use my wife as a spark tester, she screams if there is a spark. If you are single you can buy one for under $10.
Take a voltage measurement, KEY ON, input and output of the ballast resistor. You are looking for a voltage drop across it, say 6 volts or so.
This voltage drop will verify the following:
That the DS2 box is power ON and has a good ground
The coil primary has current flow and that the primary winding are good
That the primary Ignition has a good ground
The amps draw is in the normal range, to get a hot spark
Good luck, Jim
The round coil and the square coil use a different coil wire as the coil end is different. Most new wire kits have both in the box to cover more truck years. Make sure the coil wire fits correctly. I use my wife as a spark tester, she screams if there is a spark. If you are single you can buy one for under $10.
Take a voltage measurement, KEY ON, input and output of the ballast resistor. You are looking for a voltage drop across it, say 6 volts or so.
This voltage drop will verify the following:
That the DS2 box is power ON and has a good ground
The coil primary has current flow and that the primary winding are good
That the primary Ignition has a good ground
The amps draw is in the normal range, to get a hot spark
Good luck, Jim
Moderator
Joined: Jan 2001
Posts: 56,992
Likes: 2,741
From: Virginia
Below is the diagram for a 5.0, 302 fuel injected engine in 1986. You can see it still has the resistor in the wiring, but it's not being used. It still has the same c321 and c325, but they are being used differently. But they are being fed the same voltages that they are in the duraspark II diagram. They are the same connectors between the two ignitions, the connector c321 is the one that is attached to the duraspark II module, it is the same connector as the one used in the fuel injection wiring.
Thread Starter
|
Cross-Country
Joined: Dec 2019
Posts: 93
Likes: 0
First of all I’m sorry I haven’t gotten back but I had one visitor after the next yesterday —Maybe I’m missing something but I looked at the schematic I drew and the painless schematic, I have the brown wire going from positive coil to the “I” on the relay and the other red wire coming off positive coil to one side of the ballast -is that not correct?
Moderator
Joined: Jan 2001
Posts: 56,992
Likes: 2,741
From: Virginia
First of all I’m sorry I haven’t gotten back but I had one visitor after the next yesterday —Maybe I’m missing something but I looked at the schematic I drew and the painless schematic, I have the brown wire going from positive coil to the “I” on the relay and the other red wire coming off positive coil to one side of the ballast -is that not correct?
Thread Starter
|
Cross-Country
Joined: Dec 2019
Posts: 93
Likes: 0
The blue/white from the (keyed) from the ignition to the ballast then back to the red on module
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
3 Best / 3 Worst Parts of Modern Ford Ownership
Brett Foote
10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches
Pouria Savadkouei
Every 2026 Ford Engine Explained
Brett Foote
10 Ugly Ford Trucks That We Still Kinda Love
Joe Kucinski
10 Things Every Truck Owner NEEDS (2026 Edition)
Michael S. Palmer
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath
Verdad Gallardo
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer
Joe Kucinski
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)
Brett Foote
Top 10 Ford Truck Tragedies
Joe Kucinski
Cargo Master
Joined: Jan 2019
Posts: 3,369
Likes: 16
From: Caraway, AR
You mean where the wire to the cap goes? Not sure I'd put a tester on that, not sure what the voltages values are but it's enough to smoke a DVOM. I'm not quite sure how the system works. I assume the coil - has a lot to do with it.
