Crank but no start- 68 Charger

[whitehatspecial]

I just installed the rebuilt 904 back in my '68 charger and as soon as reconnected the battery ground (no key) I heard a pop in the engine bay.

The starter still cranks, lights, horn, heater fan, and fusible link is good (tested power on the connection block.

No radio or emergency flashers and no power to the Distributor.

Update. Went through this today and here's an update. The "pop" happened again so whatever is happening it is resetting itself. This happens with the ignition key in the off position and when connecting the battery. No blown fuses.

My neighbor and I checked/ ohmed out the positive battery cable, and ignition wiring brown and dark blue. The pop noise seems to be coming from the passenger side of he engine bay near the coil, but haven't been able to see a spark or arc. Engine will crank.

What is hot without the ignition on that could cause this?   

[70 sublime]

Try un hooking the big red wire on the alternator and see what happens

[Kern Dog]

What red wire to the alternator? The positive wire/charge wire is black.

[70 sublime]

OK the heavy wire to the alternator

[whitehatspecial]

Thank you!! I will check that out today. I'm sure it's something really stupid as everything was fine prior to pulling and replacing the tranny. Shit happens, I guess.

[b5blue]

Look for a short to the neutral safety switch?   

[Arigmaster]

Ballast resistor on the fire wall?

[XH29N0G]

I do not have an answer and it sounds to me like your approach with a multimeter and tracing the wires is the same as what I would do.  I believe there are live circuits (like the lights) that work when the key is in the off position, but I am under the impression that the key should interrupt everything (I have not gone back and traced out the wiring diagram in the FSM - which I assume you are doing).  The fact that you have a pop and something happens when you connect the battery, suggests to me that you have something either shorted or wired incorrectly.  Does your multimeter also have an ammeter setting.  You could check to see what you draw between the cable and battery.  I would also think you could check for any voltage between battery and the main cable.

these are just thoughts and shots in the dark.  I hope they help.

If you do not have an FSM, I can dig mine out for a 197o to see if I see anything with that.  Since this happened with the reinstall of the 904, I would look there.  Interrupts or backup light? Then to other things I might have changed or knocked.  I had some old wires that were cracked and exposed.  If you have a similar situation, it could be somewhere else in the circuit.

[whitehatspecial]

XH29N0G and all that have responded.

Thank for your reply. This is definitely a head- scratcher but I'm pretty sure we're on the right track. I did remove the positive cable off the battery and ohmed it for a ground fault, and then re-installed it, and tested for an amp draw with no key. Nothing found on those tests.

I'm leaning towards the ballast resister as it has a small coil/ spring which may reset, also the porcelain is cracked on the back side. I have a new one coming this week. Also have a factory manual and have studied the wiring diagrams for tracing the issue. I also need to pick up some dielectric grease to apply to the bulkhead connections after I clean them. The don't looked too bad as this is 50000 mile car which has been garaged for most of its life.

I'm pretty sure it's not the neutral safety switch as the starter runs in park or neutral but not other selections.

[70 sublime]

I think when you turn the key the resistor is by passed to give the coil a little more voltage to start the car and after you let go of the key to the run position the coil gets less power because it goes through the resistor

Do you have the narrow resistor with just one connection on each end ?

[whitehatspecial]

Yes the ballast resistor is the 2 terminal type.

[b5blue]

Is it stock points?

[whitehatspecial]

No points. The motor is a 340 with a Mallory magnetic breakerless distributor. I've had this setup in the car since 2006 when I pulled the original 318.

[white]

D

[Kern Dog]

? ? ?
If the neutral safety switch is working, the car wouldn't even crank over. It disables everything, not just the spark.

[ACUDANUT]

? ? ?
If the neutral safety switch is working, the car wouldn't even crank over. It disables everything, not just the spark.

True Dat !!! All kinds of worthless advice here. 

[whitehatspecial]

It's all good guys. Awesome that you're reading my posts and offering assistance. Trust me I need it!!

Question: I'm cleaning the bulkhead connectors to eliminate any gremlins or possible bad connection. They don't look bad, no corrosion but it's really hard to see inside the female firewall connections. Any advice as how to clean those? I was thinking of some kind of pick, but I didn't want to get too aggressive. I will be using a little dielectric grease when reconnecting.

[whitehatspecial]

Ballast resistor on the fire wall?

The ohm reading for the ballast resistor are all over the place, so I'm replacing it. After the "pop" I was getting "OL" with no resistance. After it must've reset itself it jumps from .5 to 2.4 ohms, so something isn't good. Thanks

[70 sublime]

Your ballast resistor

Each end has a wire connection
Is there 2 wires in the connector on one end that leads to the coil and a single wire in the other connection ? 

[whitehatspecial]

Yes.

[b5blue]

? ? ?
If the neutral safety switch is working, the car wouldn't even crank over. It disables everything, not just the spark.

True Dat !!! All kinds of worthless advice here. 

More like worthless comments, 50 year old cars can have anything not to spec./cobbled/changed/missing! Stop assuming textbook situations and over emotional pointless remarks. See how I worked "pointless" in there, your wisecrack and his ignition are both POINTLESS... (Notice the lack of even one emoji.)
  Now the N.S.S. only enables the starter relay in PARK or NEUTRAL. It is not part of ignition from the factory. (Check your FSM.) 

[Kern Dog]

Once you become a Moderator, you have the right to edit content. Until then, since you have the same level of authority as others, your words carry the same weight.

[timmycharger]

Once you become a Moderator, you have the right to edit content. Un til then, since you have the same level of authority as others, your words carry the same weight.

Nah.. it's a matter of opinion as to whose words carry weight. 

? ? ?
If the neutral safety switch is working, the car wouldn't even crank over. It disables everything, not just the spark.

True Dat !!! All kinds of worthless advice here. 

Alright A-NUT, enlighten us on your wisdom of how the OP's issue can be fixed 

Oh.. and please try to respond w/o sending me a nasty P.M. like last time? Something about my wife or something? ring a bell? 

[birdsandbees]

Too late in the season for "winternet" guys...

[DownZero]

It's all good guys. Awesome that you're reading my posts and offering assistance. Trust me I need it!!

Question: I'm cleaning the bulkhead connectors to eliminate any gremlins or possible bad connection. They don't look bad, no corrosion but it's really hard to see inside the female firewall connections. Any advice as how to clean those? I was thinking of some kind of pick, but I didn't want to get too aggressive. I will be using a little dielectric grease when reconnecting.

Try a small "points" file or jewelers file and lightly scrape into each female socket. Spray entire bulkhead connector with electrical contact cleaner or brake cleaner. Blow out excess and apply a liberal amount of dielectric grease.