Pulling my hair out.. Ignition. not starting

[pedal2themetal]

HI,
1975 Fury 318.
I'm at a loss.. Here's what it does and what I've had done.......
What it does,
Works fine for a while then it well turn over great and fast. but NO start, unless I barely turn the key.. an sometimes that don't work its worse now .. even barely turning the key doesn't always work.. and I mean Barely have to find the sweet spot.. and its a verrrrry small spot..
Whats been replaced
I've had the switch replaced 4 times 2 by me and 2 by shops the last one was a NAPA over $100.oo part installed by a shop as well as the key switch... In January this year 2022. It works fine for about a month then starts getting worse and worse. to where we are at now barely works.
Coil replaced , ballast resistor like 3 times last time by shop
I've cleaned the connection at the resistor wire thinking that might be it.. but NOPE..
I'm about ready to just put in a button that adds 12V to the coil to use when starting..
any help well be appreciated
thanks , take care, be safe
tim

 

[twecomm]

You might want to obtain a schematic for your cars electrical system. The wiring for problems you are chasing pass thru the bulkhead connector. Based on everything you say, that would be a good place to start looking for a problem. Inspect every connection, look for over heated wires, bad crimps or indications of corrosion (green coloration of copper wire at crimp) on connector pins.

 

[Tony Tee]

Maybe check for loose and burnt wires / connectors at the bulkhead connector on both sides of the firewall?

 

[pedal2themetal]

HI OK I'll look . could the switch be turning in it holder?? I forget how it is mounted. been awhile since I"ve replace it my self.
tim

 

[YY1]

Does it start by jumping the terminals on the relay?

 

[Don Frelier]

From what you've indicated its almost certain you are not getting power from the keyswitch to the start side of the ballast resistor in the start position.
I would disconnect the wire to the starter relay, put a meter on the ballast resistor and check with the key in the start position.
Track that wire from the resistor to the keyswitch (likely a problem in the bulkhead).
Like @twecomm suggests get a copy of the schematic for your car to help identify the colors and wiring.
Get someone who can read a schematic to help if necessary.

 

[RemCharger]

Is the switch down lower driven by a rod? Could it be adjusted

 

[pedal2themetal]

Thanks I'll check that stuff..
Not sure but I don't think is operates a lever or rod??

It really seams like its switch related tho.. as after a short time it gradually get worse (having to turn it less and less into the start function) and once it starts getting worse in a week or short you well have to find that tiny sweet spot.
thanks again take care be safe
tim

 

[YY1]

The "switch" is in the back of the cylinder.

I have seen them go bad a time or two.

Can you start it by jumping the relay on the firewall?

It's simple process- with the key in the "run" position put a flat blade screwdriver almost straight down touching the large post and the one above it.

 

[super-bee_ski]

I had same issue, I converted to Electronic Ignition...fixed it
May not be your issue, but it was mine

 

[Don Frelier]

I had same issue, I converted to Electronic Ignition...fixed it
May not be your issue, but it was mine

1975 would be electronic ignition.

 

[pedal2themetal]

Can you start it by jumping the relay on the firewall?

It's simple process- with the key in the "run" position put a flat blade screwdriver almost straight down touching the large post and the one above it.

HI YY1. Nope doesn't start spins it up but no start.. on my relay the solenoid wire is under the big wire.. still no start.
The switch and key tumbler are both only 2 months old Napa parts..
I got a button a while ago and I'm just going to jump the coil from the battery when starting and see if that does it..
Man I hate electrical problems..
thanks take care, be safe.
tim

 

[YY1]

Did you try "jumping" the ballast resistor?

Basically the same as hot wiring the coil.

Bad ballast is fairly common, more common that bad ignition switch.

Why was the ignition switch replaced?

 

[dvw]

Pretty simple. The colors here may be inaccurate, don't know. The ignition 1 circuit feeds pin 1 at the ignition box. it also feeds into the 5 ohm resistor to pin 3 at the ignition box. The last feed is to the 1.2 ohm resistor going to the coil +. All these points will be hot in the run position. The ignition 1 circuit goes dead in key crank position. The ignition 2 start circuit goes hot in crank only. However it feeds thru the 1.2 ohm resistor then doubles back feeding the 5 ohm resistor thus feeding voltage to every spot mentioned above. When you release the key Ignition 1 becomes hot again and ignition 2 goes dead. As you can see if any of these connection or one of the resistors is open there will be no power thru any ignition components while cranking. I believe you will find that is the issue. Use a test light while a helper work the key. Disconnect the resistor connectors to test the circuits from the key. The wire indicated as orange will be hot in run, dead in crank. The wire indicated as pink will be hot in crank only.
Doug

 

[Crackedback]

ballast or the bulkhead where the IGN 1 and IGN2 pass through.

I had one where the bulkhead test good when probing because the terminals were forced together just enough to connect. Pull probe, no connection. That was fun. I'd test the wires on cabin side first to make sure IGN1 and IGN2 are hot when supposed to be and then test at ballast. If one is dead, you narrowed the source down.

 

[pedal2themetal]

Did you try "jumping" the ballast resistor?

Basically the same as hot wiring the coil.

Bad ballast is fairly common, more common that bad ignition switch.

Why was the ignition switch replaced?

Hi,
Ballast is New and is the second or third one new.. Didn't try jumping that.

the Switch was replaced 3 or 4 times lost count ,due to no start . The Key switch was changed he said it was loose? Now I have two ign. keys the old one for the doors and new one for ign.? Car only has 76 T miles on it.... I told the last shop about it starting to not work already.. He told me he well warranty the parts..when he installed it...

I tried jumping the coil from the solenoid post on the relay and it would start right away but die the second I let go of the key?? thought it would stay running cause I didn't take away any wires??

Its starting now but for how long some times its a hit and miss on starting, anyway I went ahead and just added the button to add 12 V to the coil .. Going to try that next time is don't start..
uuggg frustrating.. It could be a early as in the morning for it not to start or later today...

thanks take care, good luck be safe,
tim

 

[pedal2themetal]

View attachment 1261894

Doug

HI Doug
Mine has two wires going to the coil + posistion..
Tim

 

[Don Frelier]

HI Doug
Mine has two wires going to the coil + posistion..
Tim

It could be that the wire from the ignition switch (START) goes right to the coil and not to the ballast as shown on the diagram.
It would function the same either way.

 

[Fran Blacker]

Has anyone said check the plug where it comes out of column to harness. Had a 70 Coronet wouldn't start the white plug had burned area, there it was.

 

[pedal2themetal]

It could be that the wire from the ignition switch (START) goes right to the coil and not to the ballast as shown on the diagram.
It would function the same either way.

Hi, yes but my ballast has 4 wires in it two in and two out? so I don't know?? OH its all stock ..

Thanks
tim