by fordconvert » Thu Nov 05, 2009 10:08 am
2 wire plug on the module:
Red= goes to the r(run) terminal on the key. So that should be full system voltage when the key is in run.
White= goes to the s(start) terminal on the key. That would be full system voltage when the key is in the start postion, this is used to retard the timing for easier starts.
4 wire plug on module:
Green= goes to the - terminal of the coil. THIS IS NOT A GROUND only optional thing to hook here is a tachometer signal wire.
Orange= to pickup in distributor
Purple= to pickup in distributor
Black= Ground connection in distributor. The module also grounds through its body.
Coil connections:
- = is the green wire to the module and an optional tachometer NOT A GROUND
+ = Same run terminal of the key that the above red wire hooks to except that after the red wire taps off there is a ballast resistor wire. When running this would be more like 8 volts. There is also a second (s)start terminal on the key that then connects after after the resistor to send full system voltage to the coil during cranking.
It looks complicated but its really not. For a test just get +12 to the red wire of the module and + of the coil it should start and run as long as the green is hooked to the - of the coil and the orange and purple are hooked up.
If you unplug the harness going to the dizzy and hook an ohm meter to the orange and purple you should get a steady reading. If you flex the wires around it should stay steady. If you have a hand vacuum pump operate the vacuum advance and make sure it stays steady. If you spin the dizzy (crank engine) you should see steady pulses.
Normally I think Haynes manuals are worthless. For some reason I have one for the Ford trucks. #36058 (880) Ford Pickups & Bronco 1980-1996. Red cover with white and yellow lettering. A cutaway sketch of an F250 on the cover. It has about 3 pages on testing the Duraspark system using basic tools. These manuals are in stock at most parts stores for around $15. I would think any Ford repair manual from 75 to around 85 would also have the same basic info since the system was the same in the cars. If you dont have any sort of manual it may be worth getting one. Factory type are the best but often harder to find and more expensive. In this case a Haynes will get you through this problem. Another option is many public libraries have repair manuals in there reference sections. Those that dont usually have free access to ALLDATA online which is the service many shops use. You just have to pay to print pages. It takes a while to get how to navigate the site but once you get it figured out there is tons of good info including complete trouble shooting and electrical drawings. You can also go to their site from home and pay for the DIY service. Its like $30 for 1 year of access to only one car. Extra cars cost extra. Seems like every time I have paid for that I have sold the car so i just go to the library and do it for free. Shops pay like $100 per month for access.
Electronic devices like the module dont tend to sort of work. The usual portion of them that fails is the actual switching device. There are 2 common failure modes of electronic devices. Shorted which basically means its stuck on which would do things like melt a coil. The other option is open which means it does nothing. Its extremely rare for either of those things to happen intermittently. Thats the work or not work part. One thing that could happen is the device shorts and due to the load of the shorted out melted coil something in the circuit melts and then opens. Its possible that some of the driving circuits have failed but I dont think its that common. I have read that there are 2 sections to the module, one for running and the other one for starting. I have heard of cases where it wont start but as you let go of the key it will suddenly fire and run. Same thing the other way where when cranking you can feel it fire but as you release the key it quits.
TJ H
'66 Mustang coupe {her toy}
Stock 200, DurasparkII/HEI, AT, Scarebird 5 lug disc with SSBC power MC kit.
'73 Cad Eldorado Convert w/Megasquirt TBI{my toy} '97 Tahoe {her DD} '05 Hemi Magnum {my DD}