Why won't is stay running

[429bossman]

Question . Key switch has to stay in start mode or engine dies .As long as you grind on the starter it will try to start let go and let it come back to run position engine dies. 440- 6 70 GTX. Thanks

 

[Kern Dog]

You're new to Mopars, huh?
This is a classic case of a bad ballast resistor.

 

[429bossman]

Thanks for the fix . The ballast this is what happens when all been working is Fords . You over look simple things . Thanks again

 

[Kern Dog]

I had one Ballast resistor do this:

Yeah, the spring that connects one side to the other just broke.
It was weird...The car was running but then stalled when I shut the hood. It would try to start but wouldn't stay running. My guess is that the spring was old and brittle...and just snapped from the vibration of the hood closing. This could have happened while driving down the road.

 

[429bossman]

OK is there different for a dual point . Are they all the same ?

 

[70 sublime]

When you turn the key to crank the engine a wire that goes direct to the coil powers up and bypasses the ballast
When the key is in run mode there is a wire that goes to the ballast that powers up and the crank wire goes dead

Single point or dual point distributor all get the power the same way from the key

 

[turbine68rt]

Make sure the spade connector is tight on the blade. I already had one come loose on the highway and died. Did the typical start/die of a bad resistor, but it was a matter of pushing it back on. Squeezed it tighter and never happened since. Repro harness.

 

[s/w theo]

Mopar guys ALWAYS keep a spare one of these in the glove box.

 

[AR67GTX]

OK is there different for a dual point . Are they all the same ?

There may be a small difference in ohm rating for dual points vs single system depending on the specified coil. If you have a factory service manual for your car you can look up the coil and ballast resister specs for your engine. However, there’s always the chance your car no longer has the correct coil in it after all these years. I would use a multimeter to check your coils primary and secondary resistance and then contact forum member Halifaxhops and buy a coordinated ballast resister from him. It also could be you need coil and resister both, for optimal performance and points life.

 

[icetech]

Mopar guys ALWAYS keep a spare one of these in the glove box.

I always carried a spare and never had one die that's the trick to it

 

[eldubb440]

Mopar guys ALWAYS keep a spare one of these in the glove box.

along with a spare condenser if running points........ non smokers use the ash tray

 

[turbine68rt]

Early 90's a co-worker had a 71 Swinger. Drove by his place and saw the hood up with 3 guys working on it. His non Mopar buddy spent hours replacing the ignition switch, only for it to continue to start then die. I pulled a spare br out of my toolbox, swapped it out in a minute and it fired and ran. I think that guy wanted to choke me.

 

[eldubb440]

I distinctly remember the day I learned about ballast resistors....and the day I learned about condensers........lessons for life lol

 

[68BabyBlue]

Make sure the spade connector is tight on the blade. I already had one come loose on the highway and died. Did the typical start/die of a bad resistor, but it was a matter of pushing it back on. Squeezed it tighter and never happened since. Repro harness.

I had the same thing happen with my A33 GTX, but the bad connection was at the firewall block, figured it out after I tried changing the ballast resistor with no success. Cleaned up the spade and never had another problem.

 

[davek]

Question . Key switch has to stay in start mode or engine dies .As long as you grind on the starter it will try to start let go and let it come back to run position engine dies. 440- 6 70 GTX. Thanks

Did you figure it out?

 

[429bossman]

I ordered two new resistors from Ebay . One for the car and a extra. Thanks to all for your help.

 

[Crackedback]

engine off with key in run.

Probe each side of the ballast resistor for power and voltage readings. If one side has power and other side is dead, you found at least part of your issue.

Both sides dead, look at bulkhead where the brown and blue wires (ign1/ign2) pass and probe there. They can be an issue after 50 years. May not be the ballast that is the issue.

 

[429bossman]

Up date it was a bad connection from the steering column to the car harness . Cleaned the connection and it started . But in the mean time I had blown both mufflers off the car . I guess I was trying to hard to start the car and loaded them with fuel .

Thanks again to all for input. I got a good education from all the ideas . Are the mufflers OD 2.25 or 2.50 ?