Originally Posted by ccawadew
Sorry, I have an '85 with a 258. It is stock, although the wiring has certainly been buggered with plenty.
'Red' wire to module getting power in 'Run' position.... Correct.
'Blue' wire to module getting power in 'Cranking' position... Correct.
'Red wire at coil getting reduced voltage (Dim Light) in 'Run' position... Correct.
'Red' wire at coil getting full voltage (Bright Light) during cranking... Correct.
Your ignition switch, resistor, fuse, ect. all check out,
The 'Issue' is with the engine bay side of the ignition.
I didn't see any mention of the Stator (Distributor Trigger) being checked for 'Ground'...
You simply connect to ONE of the parallel terminals in the trigger connector, and probe the distributor body...
Repeat on the other parallel terminal.
You should show an OPEN circuit.
If you show ANY connection between either of the parallel terminals and ground, then the stator is shot...
Wouldn't be the first one that came out of the box bad!
'Green' wire at coil getting 'Ground' Takes a positive feed from battery to 'Green' wire to find that out... Still waiting....
You missed one test...
Connect to POSITIVE with your test light,
Probe NEGATIVE to see if light is working.
Then DISCONNECT the coil connector, probe the 'Green' wire.
You should get a 'Bright' light.
Then crank the engine and probe the 'Green' wire,
You should get a 'Flashing' light.
If you don't get a 'Flashing' light,
1. The module isn't grounded, can't complete the coil circuit if the module isn't grounded through it's 'Black' wire.
Module grounds through the distributor housing.
2. The trigger signal isn't getting to the module,
That can be connectors, grounded wire someplace between distributor and module,
3. The module is bad and isn't switching with the distirbutor signal, wouldn't be the first time a bad module 'Tested' good when some 12 year old at the discount store didn't know what he was doing...
4. Or the 'Green' wire is compromised between coil and module, keeping the coil from completing it's circuit.
If you get flashing at the 'Green' wire like you are supposed to, it's the coil since everything else is working...
Positive to green coil connector terminal...
This tests the engine engine bay side of the ignition, except for the ignition coil...
The positive from the battery will flow through the 'Green' wire to the module and 'Ground' through the module if the module is 'Grounded'.
This will give you a steady 'Bright' light.
When you crank the engine,
The distributor *SHOULD* send a signal to the module to switch the current to the distirbutor 'On/Off'...
As the engine rotates, the test light should 'Flash' On/Off as the module opens/closes the coil circuit.
If you don't get the flashing at the green wire as you test the coil 'Ground' circuit, then something is wrong.
Either the module isn't getting 'Ground', which you test with the 'Constant Bright' test before you crank the engine...
Or the Trigger signal isn't being produced, or it's being blocked to the module,
Or it's not being processed by the module.
Since you KNOW the module is powered up, (Module 'Red' & 'Blue' wire tests),
And you KNOW the module has 'Ground', (Constant 'Bright' on the 'Green' coil wire before cranking)
It has to be signal getting to the module, or the module it's self.
If you get the Constant 'On' and the 'Flashing' at the 'Green' coil wire,
Then the only part of the system that can still be causing trouble is the ignition coil it's self...