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.

[70 sublime]

Yes.

Your car should run with the key in the cranking position if there is any power getting to the double end of the wire even if your ballast is bad
If ballast is bad the car will die as soon as you let the key return to run position if it started while cranking

Did you ever try starting the car with the big BLACK wire un hooked off alternator ?

You said there is a pop sound that comes from passenger side and that is about the only thing left with power wires on that side
The alternator could be grounding out for some reason ??

[ACUDANUT]

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?  

What the heck are you talking about ?  I don't know you or your wife ??  

[whitehatspecial]

Yes.

Your car should run with the key in the cranking position if there is any power getting to the double end of the wire even if your ballast is bad
If ballast is bad the car will die as soon as you let the key return to run position if it started while cranking

Did you ever try starting the car with the big BLACK wire un hooked off alternator ?

You said there is a pop sound that comes from passenger side and that is about the only thing left with power wires on that side
The alternator could be grounding out for some reason ??

I am waiting for some Deoxit D5 contact cleaner to spruce up the bulkhead connections, so no I haven't tried to unhook the alternator yet. A photo is below, I don't see a large wire just what's pictured. I will try that, my damn full time job keeps getting in the way!!

[RiverRaider]

It looks like a later hi amp alternator.  Is it just the picture angle or is the terminal on your green field wire burned off?  Before you posted the picture I had this idea.  As it was mentioned that you do not have points if that is correct has the engine harness been spliced to run electronic ignition or is it an aftermarket ECU harness ?  Either way I would trace each wire back from the alternator to the bulkhead looking for shorts.  I have experienced wires shorting together on the engine harness between the passenger side valve cover and the carb.  There could be some other issues relating to the newer alternator but I would suggest these two places first.  Good luck.

[whitehatspecial]

The green alternator wire is intact and the connector is tight. Interestingly I did check the alternator connection and probably got a full turn or more on the nut that holds the field wires on. The wiring on the right side valve cover all look good. I will have the bulkhead connections cleaned and have everything together this weekend.

I plan on having all the lights off in the garage when I hook up the battery so that if it "pops" again I'll hopefully be able to pinpoint the arc.

Thanks again for the advice.

[Kern Dog]

I apologize for not reading every response. I may rant on about stuff already covered so bear with me...
I have electronic ignition in both of my '70 Chargers. There is one blue wire that connects to the alternator, coil positive and the ballast resistor.   The coil negative wire is a black with yellow tracer. If either of those is damaged, you'll get no spark.
When I have a NO spark condition, I often try swapping parts from my stash. I've had ballast resistors fail instantly where the car starts and runs fine one minute, then wouldn't. I've had the winding inside actually break. 
The factory electronic ignition box needs a good ground. I add an additional ground wire to ensure proper function.
You could run a wire from battery positive to coil positive, effectively energizing the coil directly. If the car won't start after that, the coil is not to blame.
I've had instances where I can crank and crank, then as I am releasing the key from the spring loaded "crank" position, the engine comes to life. Some blame the ignition switch for that, maybe they are right but to test that, I've plugged another ignition switch in and had the same symptom.

[whitehatspecial]

  Almost too embarrassed to post this, but I located the issue. When I pulled the transmission I read that I should remove the distributor cap (340 LA) so it wouldn't get damaged. In addition the pulling the cap and flipping it out of the way, I removed the rotor. I didn't even notice it wasn't there when I flipped the cap back on. It was sitting on my workbench.

Let me have it! I deserve it, but at least I went through my under hood electrical looking for problems.

Thanks again to all that tried to help.

[Kern Dog]

Bless you for your honesty. 

[70 sublime]

It's OK

I believe we all have had those days 

[XH29N0G]

I had heard of that as an anti theft measure, but now I know it can be something else.  I am glad you figured it out.   

[ACUDANUT]

Who among us is perfect ?

[nchrome]

l'm next to perfect l forgot to gap the points once  ::)lol

[Kern Dog]

l'm next to perfect l forgot to gap the points once  ::)lol

Same here. The first time I changed points, I just swapped them in. I knew nothing about setting a gap. I called a buddy.....
I just changed the points and It won't start.
He asked...."What are they gapped at?"
Gapped? Huh ??