Engine Died While Driving

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Gamedog

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As title says, was out in the 70 Dart and the motor cut out.

Quick facts:

- Original Slant 6/904 column shift car
- Now a 408/904 B&M floor shift
- Fuel in carb and electric fuel pump still works, so it's not a fuel problem
- No power to anything run off of ignition switch ie: key buzzer, ignition, radio, lights, dome lights, etc
- Switched out turn signal switch a few days ago
- Disconnected and reconnected the Starter and Ignition Switch Connector as it made it easier to fish signal switch wires through steering column
- Alternator (swapped from my slant 6, likely underpowered) shows constantly pinned to charge when throttle is applied
- Ignition system consists of MSD 6AL, MSD Coil, MSD wires
- Aftermarket radio and (1) 6x9 speakers which recently started to have issues ie: only works when brake is applied under 20 mph or so - not sure if related but thought I'd bring it up
- Holley Blue Electric fuel pump run off manual switch straight off of battery
- Electric Fans running straight off of battery

I plan to get under the dash and disconnect, reconnect Starter and Ignition Switch Connector since that is what I touched last, but would a loose connection cause my motor to die?

My first thought was my alternator, but before I go buy a replacement (looking at Powermaster 7509 - thoughts?), figured I'd ask the electrical gurus ( @67Dart273 & @TrailBeast come to mind) on here for some input.

Also wondered if it was my neutral safety switch, but the fact that I have zero power to anything rules that out...

Hope I provided enough info, if not please let me know what else y'all might need...

Thanks in advance!
 
You need to trace the power coming from the battery through the bulkhead connector. Could be your fuse link or the bulkhead connector. 65'
 
As title says, was out in the 70 Dart and the motor cut out.

Quick facts:

- Original Slant 6/904 column shift car
- Now a 408/904 B&M floor shift
- Fuel in carb and electric fuel pump still works, so it's not a fuel problem
- No power to anything run off of ignition switch ie: key buzzer, ignition, radio, lights, dome lights, etc
- Switched out turn signal switch a few days ago
- Disconnected and reconnected the Starter and Ignition Switch Connector as it made it easier to fish signal switch wires through steering column
- Alternator (swapped from my slant 6, likely underpowered) shows constantly pinned to charge when throttle is applied
- Ignition system consists of MSD 6AL, MSD Coil, MSD wires
- Aftermarket radio and (1) 6x9 speakers which recently started to have issues ie: only works when brake is applied under 20 mph or so - not sure if related but thought I'd bring it up
- Holley Blue Electric fuel pump run off manual switch straight off of battery
- Electric Fans running straight off of battery

I plan to get under the dash and disconnect, reconnect Starter and Ignition Switch Connector since that is what I touched last, but would a loose connection cause my motor to die?

My first thought was my alternator, but before I go buy a replacement (looking at Powermaster 7509 - thoughts?), figured I'd ask the electrical gurus ( @67Dart273 & @TrailBeast come to mind) on here for some input.

Also wondered if it was my neutral safety switch, but the fact that I have zero power to anything rules that out...

Hope I provided enough info, if not please let me know what else y'all might need...

Thanks in advance!

Wow, lots to take in there, and these kinds of problems can seem overwhelming but don't let it swamp ya.

I have a way of keeping it simple, and probably won't give you a ton of "do this and check that" items but more eliminate one or two things at a time.
Full charging issues usually come from a large draw somewhere, like a short or a battery that won't take the amps the alternator puts out.
Have you disconnected the bulkhead connector and inspected it for heated or melted contacts?
This is a prime source of multiple electrical issue's

You might also pull all the fuses and see if the problem persists.
This will disable pretty much all the accesories, but may give a clue where the problems are coming from.
If some problems stop with the fuses out, then putting them back one at a time a testing again could point out more specifically where the problem circuit is.

Let us know your results.
 
You need to trace the power coming from the battery through the bulkhead connector. Could be your fuse link or the bulkhead connector. 65'

Well would you look at that...

20200524_082539.jpg


20200524_082709.jpg

Man, so what would have caused this?!

I'll dig into this in my service manual...
 
Wow, lots to take in there, and these kinds of problems can seem overwhelming but don't let it swamp ya.

I have a way of keeping it simple, and probably won't give you a ton of "do this and check that" items but more eliminate one or two things at a time.
Full charging issues usually come from a large draw somewhere, like a short or a battery that won't take the amps the alternator puts out.
Have you disconnected the bulkhead connector and inspected it for heated or melted contacts?
This is a prime source of multiple electrical issue's

You might also pull all the fuses and see if the problem persists.
This will disable pretty much all the accesories, but may give a clue where the problems are coming from.
If some problems stop with the fuses out, then putting them back one at a time a testing again could point out more specifically where the problem circuit is.

Let us know your results.

Thanks TB!

Looks like the Fusible Link in my bulkhead connector is fried...

Looking at my service mahul, looks like this ties to my ammeter, which is tied ti the alternator it seems.

Could my alternator be the root cause here?
 
Thanks TB!

Looks like the Fusible Link in my bulkhead connector is fried...

Looking at my service mahul, looks like this ties to my ammeter, which is tied ti the alternator it seems.

Could my alternator be the root cause here?

Well that'd do it. :D
Right now I doubt the alternator is bad.
Most likely your charging went nuts due to the charge not having a solid place to go.
I would start by fixing that Fusible link situation and go from there.
BTW, I ripped that link out of my car the first day I had it, and replaced it with a 30 amp self resetting circuit breaker.
Something designed to burn up under the hood just didn't sit right with me.:D
I have not had one problem with the 30 amp breaker, but some disagree with using them in place of the link.
 
It’s time to look at bulk head connector and possibly bypass it. Too much resistance in connector will cause fusible link to melt like that.
 
Well that'd do it. :D
Right now I doubt the alternator is bad.
Most likely your charging went nuts due to the charge not having a solid place to go.
I would start by fixing that Fusible link situation and go from there.
BTW, I ripped that link out of my car the first day I had it, and replaced it with a 30 amp self resetting circuit breaker.
Something designed to burn up under the hood just didn't sit right with me.:D
I have not had one problem with the 30 amp breaker, but some disagree with using them in place of the link.

Gotcha, thanks!

Do you have a picture what your setup looks like in lieu of the fusible link?
 
It’s not difficult at all. You already have to replace fusible link. You will most likely have to pull instrument cluster to get to amp meter connections.
 
It’s not difficult at all. You already have to replace fusible link. You will most likely have to pull instrument cluster to get to amp meter connections.

If I did this, would it eliminate my ammeter entirely? Was thinking of converting to a volt meter so I'd still like to use of possible.
 
Yes it jumps across it so it is then inop. You can still add a volt meter easily .
 
It does eliminate the meter but it can be replaced with voltmeter. Lots of examples in electrical section of forum. Let me see if I can find a example
 
Gotcha, thanks!

Do you have a picture what your setup looks like in lieu of the fusible link?

I don't currently have a picture of it in the car, but it's just an automotive 30 amp self resetting breaker in place of the fusible link section.

Also, keep in mind a volt meter can't be wired like the amp meter.
The volt meter needs to be on keyed ignition power and grounded.
The amp meter is a pass through type gauge, and the volt meter isn't.
 
Gotcha, thanks!

Do you have a picture what your setup looks like in lieu of the fusible link?

I'm going to be doing another photo/video set today and will get a pic of the relay and how I connected other aftermarket accessories to it while I'm at it and post it later for you.
Pretty much everything in my car is on fused relays and circuit breakers, and I run almost all LED's in the car except for the headlights, and those are GE Nighthawks on relays fed direct off the battery.
So this means power drain in the car wiring and switches is greatly reduced.
I can run every electric device in the car without dimming headlights, heater blower or wipers slowing even at idle.
 
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I'm going to be doing another photo/video set today and will get a pic of the relay and how I connected other aftermarket accessories to it while I'm at it and post it later for you.
Pretty much everything in my car is on fused relays and circuit breakers, and I run almost all LED's in the car except for the headlights, and those are GE Nighthawks on relays fed direct off the battery.
So this means power drain in the car wiring and switches is greatly reduced.
I can run every electric device in the car without dimming headlights, heater blower or wipers slowing even at idle.

I'm liking the sound of this more and more.

Will be on the lookout for your posts, thanks again for the help and input!
 
Looking at my service mahul, looks like this ties to my ammeter, which is tied ti the alternator it seems.
Correct, but through the main splice
Could my alternator be the root cause here?
Yes but No.
With all that additional electric equipment running, its unlikely the alternator can produce enough power at idle speeds to supply everything.
So the battery provides the power at low rpms.
Then above idle speeds, the alternator takes over again. Power from it runs the fuel pump ignition etc and recharges the battery.
Looks fairly complicated at first glance, will dig into this as a potential solution.

Thanks!
It's also a poor way to go about it.

It does eliminate the meter but it can be replaced with voltmeter. Lots of examples in electrical section of forum. Let me see if I can find a example
The meter is not the real problem. That's the other bad thing about the MAD diatribe.
The problem in this case is the wiring system is being used in a way it isn't designed for.
With a proper wiring scheme for the new equipment it may make sense to remove the ammeter. But that should be consequence, not a goal.
The goals should be:
(a) provide a good paths from the power sources.
(b) provide protection from battery shorting.
(c) If the battery is going to be relied upon to provide power, then the recharging path needs to be able to handle high charging currents.

There's more than one way to accomplish these goals.
Using an alternator that can provide more power at idle will result in less time spent at high recharging rates. I'd look into the Denso alternators.
Also may want to avoid using an AGM battery if the design will result in long periods of high recharging rate. If a battery is really low, it will suck as much power as the alternator can offer and overheat. This is the downside to using a higher output alternator. And with no ammeter, there's no way to monitor this while driving. So better to plan for it so its not a problem.

Wiring.
If the additional equipment has been wired to the battery or the starter relay, then the entire charging line from the main splice to the new junction is seeing higher loads, for longer periods of time, than it can handle.
When the alternator is turning fast enough, the system is around 14 Volts and current flows from it, not the battery.
upload_2020-5-24_14-45-0.png


In fact, when the battery needs charging, current flows to it. For example immediately after starting.
basic-charge-circuit-charging-animated-gif-gif.gif


The fusible link and all the connectors can handle 30 or 40 amps but only for a short period of time.

One short term solution might be to connect the auxilery fuse box to the alternator output. So when the engine is running, power goes directly to the fuel pump circuit and never goes through the bulkhead.
The flip side is that when running on battery power, current will have to flow through the fusible link, the bulkheads and the ammeter. Still most of the time its ther other way around. So overall this is an improvement. It also reduces peak loads on the original circuit.

Still, if that's not enough.
Then add wire connecting the alternator output and the battery positive.
So something like this.
upload_2020-5-24_15-12-25.png

The ammeter will no longer show battery charging and discharging. You can leave it or take it out. Either way, a voltmeter is needed so you have some way of judging the system while driving.

Use a fusible link on this new connection. It's not as good as having one fusible link, but its far better than none.
Fusible links are there in case the battery is accidently grounded. The short section of 16 ga wire will melt before the 12 and 14 ga wires do an arc welding show.
upload_2020-5-24_15-7-5.png
 
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When I was a kid, about 50 years ago, I had installed a Tach. ( I should have said Stupid Kid). That would happen to me and I found that the wire to the coil had worn thru and was shorting out the ignition. What gave it away was the tack went to zero before the car shut down
 
looking back on it, not many of us were smart kids. LOL Certainly not as smart as we thought we were. [who me?]
I could be a smart alec though!
 
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