Car lost all electrical while driving

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gtgto

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I was driving my 70 Duster the other day cruising in 4th gear and the car lost all power. I pulled off the road and checked under the hood. My battery connections seemed to be very tight. I tried to move the cables on the battery terminals and couldn't. I did grab the negative cable and try to move it but it didn't. Also checked where the cable connects to the engine block and all seemed good. I turned on the lights and they now came on. Got in and turned the key and she fired right up. I was able to drive home without any further issues. Would a temporary loss of ground cause all electrical in the car to shut down. I'll start with new battery cables first cause my cables have the terminal ends that clamp down on the wire.
 
Sounds like a bad ground to me. Many dont realize battery terminals are different sizes. What seems tight may just be tight to itself, but not really snug on the terminal.
Check block, firewall, radiator support grounds. There was a guy on here the other day that lost all lights bc of the small wire ground on the radiator support... I myself had the "tight battery clamp, loose on terminal" I described above when I was young. Sounds same as yours. Car would completely go dead, and magically come back alive.
 
I had a similar incident many years ago, lost all power, pulled over, checked both battery cables, etc. Car did start again after about 20 minutes of trying to determine the cause, then did the same thing a few days later. Turned out to be a short inside the battery, a plate had apparently come loose from vibration. It was a new Die Hard, replaced no charge. I have also seen the factory voltmeter cause similar issues.
 
I'd be checking those amp meter terminals and firewall electrical bulkhead for heat damage.
 
I’ve had issues with this also in a 67 Belvedere. Mine was a short in the bulk head connector. Dustin
 
^^Bulkhead connector, fuse link, ammeter connections and associated wiring. Turn on the headlights in a garage or somewhere so that you can monitor the brightness. Wiggle the bulkhead connector and associated wiring, watching for blinking, dimming, etc. Reach up under the dash and gently feel around, any heat? near the ammeter terminals. Wiggle them, looking for looseness
 
I think; Losing all power can only be caused by a break in the power circuit, between the bulkhead connector and the coil. On a running engine, if the alternator is working, you can take the battery right out of the car.
Had you said you only lost coil power, but everything else still worked, this would narrow it down to between the ignition switch and the coil.
Had you said it still cranks and starts but stalls when you release the key, this would point straight to the ballast resistor.Which is the most common Mopar ignition problem.
Had you said you smelled melting plastic that points directly to the bulkhead connector; the second most common Mopar electrical problem....... or the ammeter gauge; the third most common issue.

You gotta love it when electrical problems faith-heal on the side of the road. If you can't find the problem, remove the coil and put an ohmmeter on it; then put it in the oven at 140ish while watching the meter. Sometimes coils fail under heating.
 
I was driving my 70 Duster the other day cruising in 4th gear and the car lost all power. I pulled off the road and checked under the hood. My battery connections seemed to be very tight. I tried to move the cables on the battery terminals and couldn't. I did grab the negative cable and try to move it but it didn't. Also checked where the cable connects to the engine block and all seemed good. I turned on the lights and they now came on. Got in and turned the key and she fired right up. I was able to drive home without any further issues. Would a temporary loss of ground cause all electrical in the car to shut down. I'll start with new battery cables first cause my cables have the terminal ends that clamp down on the wire.

Lets break this apart to narrow the possible causes.

driving my 70 Duster the other day cruising in 4th gear and the car lost all power.
Driving during the day, then lights were not on. Was the heater fan or wipers on? Radio?
In other words, how do you know for sure it "lost all power"?

I turned on the lights and they now came on.
Did you try turning on the lights, before opening the hood?

Got in and turned the key and she fired right up. I was able to drive home without any further issues. Would a temporary loss of ground cause all electrical in the car to shut down.?
Possibly. The alternator case is grounded so the engine could continue running without the battery ground.

Did you notice what did the ammeter indicated when the car died? How 'bout whern you restarted?

Things that could kill the engine while driving include:
vapor lock (we're still on winter fuel and the weather hasbeen warm)
Loose connection on the coil
Loose internal connection on coil - usually fatal but sometimes intermittant.
Any ignition wire grounding out
A loose connection on any ignition wire or feed.

Losing all power requires losing both the battery and the alternator power feed.
 
Lets break this apart to narrow the possible causes.

driving my 70 Duster the other day cruising in 4th gear and the car lost all power.
Driving during the day, then lights were not on. Was the heater fan or wipers on? Radio?
In other words, how do you know for sure it "lost all power"?

I turned on the lights and they now came on.
Did you try turning on the lights, before opening the hood?

Got in and turned the key and she fired right up. I was able to drive home without any further issues. Would a temporary loss of ground cause all electrical in the car to shut down.?
Possibly. The alternator case is grounded so the engine could continue running without the battery ground.

Did you notice what did the ammeter indicated when the car died? How 'bout whern you restarted?

Things that could kill the engine while driving include:
vapor lock (we're still on winter fuel and the weather hasbeen warm)
Loose connection on the coil
Loose internal connection on coil - usually fatal but sometimes intermittant.
Any ignition wire grounding out
A loose connection on any ignition wire or feed.

Losing all power requires losing both the battery and the alternator power feed.


driving my 70 Duster the other day cruising in 4th gear and the car lost all power.
Driving during the day, then lights were not on. Was the heater fan or wipers on? Radio?
In other words, how do you know for sure it "lost all power"?

It was dusk out so I had my lights on for safety. My dash lights went out and my headlights, and the horn didn't work and my dome light also would not light. I have no radio and secondary things like heat and blower motor are not a priority and have not been sorted out. The wipers do work but they were not on at the time.
Vapor lock is a few other items you mentioned are out of the equation. I will get a chance later this week to check out the bulkhead connections.
 
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I had this. To all 3 circuits. My aftermarket Sun tach fried the year before and was still connected. Only device that had connection to Batt, ignition and auxiliary. What it was the tach started shorting out and was grounding all current. Even from batt to starter. So I suspect it's some sort of grounding issue. Maybe even body ground? Especially if you have a newer restoration? Frame paint can effect grounding circuit.

Just throwing thoughts out there.
 
It was dusk out so I had my lights on for safety. My dash lights went out and my headlights, and the horn didn't work and my dome light also would not light. So vapor lock is out of the equation. I will get a chance later this week to check out the bulkhead connections.
Good. I mean not good but answers my questions.

I think it would be odd to lose both bulkhead feeds at once. Certainly check them out, but also remove and check all the wires you pulled on that night.

Even with the alternator out, the battery should have taken over unless something either grounded out or the ground connection was poor. Grounding out should not have killed everything so quietly. Check over the fusible link for sure, and anyplace in the line before the link that could have touched ground.
 
Good. I mean not good but answers my questions.

I think it would be odd to lose both bulkhead feeds at once. Certainly check them out, but also remove and check all the wires you pulled on that night.

Even with the alternator out, the battery should have taken over unless something either grounded out or the ground connection was poor. Grounding out should not have killed everything so quietly. Check over the fusible link for sure, and anyplace in the line before the link that could have touched ground.
Thanks, I have a few things to check the next time I get a chance which looks like after work on Friday. I'll keep you all posted.
 
Voltage regulator. I've have seen plenty guys keep a few spare regulators in the car just in case. Worth a shot if you want to try for any easy fix, it's a cheap part and takes 3 minutes to replace. If the symptoms come back then you've effectively eliminated that cause.

Had a similar thing happen to me many years ago though mine was completely kaput. Was driving my old W100 down the BQE in NYC one rainy night when all of a sudden at 55mph, the truck literally dies as if the key was suddenly turned off. Managed to get it off the highway down underneath without getting killed but unlike your case, still no start, no nothing. Had it towed to a local shop, guy was old school, knew right away what it was. He was exactly correct.

Yours may be on the way out but perhaps you got lucky this time.
 
I had an Orange Box ignition module do this. It would overheat, crack the board and break connection. Let it cool and the car would start up again.
 
You should be able to take the regulator right out of the circuit and the car will continue to run on battery power. The regulator can fail in the full-fielded position and the voltage could rise to 20 at the battery, but the car will continue to run. If you catch this condition, you can pull the regulator plug and drive for many hours, periodically reconnecting the regulator and topping up the battery as you go. It's kindof a PITA at night with no flashlight, but I got home.
 
I noticed my dome light wasn't working and I put a new bulb in with no change. Found the fuse to be blown. Do you think its a coincidence from my recent electrical shutdown when driving or is it a symptom of the problem I had?
 
I had that same thing happen in my Duster. The connector from the steering column came loose. Car would just shut off. Don’t know if it was moving when I operated the clutch? I ended up resetting/replacing some of the pins but till then I’d wiggle it and push it together and the car would start
 
I noticed my dome light wasn't working and I put a new bulb in with no change. Found the fuse to be blown. Do you think its a coincidence from my recent electrical shutdown when driving or is it a symptom of the problem I had?
What else is on that fuse? and did anything other fuse burn out?

It's possible that its related.
Dome light circuit works like this.

main splice------->fuse-+-------> Dome light--------+-------> door switch-->ground.

There is always power to the dome light. Any door switch can complete the circuit to ground.
The headlight switch can also complete the circuit to ground.

The only reason for the fuse to blow is if the wire(s) between the fuse and the dome light shorted or grounded.
If it grounded after the light, the bulb would have lit up.

'67 that fuse is shared with hazzards, brake lights, and parking lights (B2 terminal on the headlight switch). '70 may be different. Need to look at the FSM and color or sketch connections. Owners manual will have the cliff notes version.
 
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Well it happened again ut this time she got a ride home on the back of a flatbed. Was driving to a local cruise I have never been too last night but didn't make it. Crusing along on some back roads in the middle of no where and the car died. I have no electrical at all....dome light, headlights or horn. The one and only other time this has happened she mysteriously came back to life and I was able to drive her home. Not this time. Ruling out things to start.....Battery is good and alternator has also been verified to be in working order.
 
You need to get a test light and/or a multimeter. A short wire with insulated aligator clips is handy too. That way you can leave the ground attached to the chassis or battery negative clamp.
Gently open the hood.
If you have multimeter, check for continuity between the battery negative post and the clamp, then the post and the chassis, then post to body.
Should be close to zero ohms on the lowest scale.
Then check for battery voltage at each accessible connection point moving away from the battery. If using a light to ground, see if it lights up when the probe touches. If using a multimeter, set it to DC Voltage. The voltage at the connection should be the same as you find at the battery positive post.
 
Here's the sequence I'd follow for the checking the positive side.
Altering it perhaps based on what I find.
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Check at the battery - that's your baseline.
Then second, at the connecting stud on the relay.
After doing the engine bay side, back probe the bulkhead connections from the inside.
Then either the column connector or the fusebox hot side, whichever is easier.
Main feed to the ignition switch (9) on your car may have red insulation instead of black. This is just a general diagram based on the late 60s cars.
Headlight switch B1 terminal is probably too difficult.
Ammeter access I don't know, but may be possible.
By this point you have found the break area or not.
If its not ground to engine or chassis, it has to be main feed since the headlights are out.
Two guys here have recently found a loose connection at the ammeter on '70 or '71 non-ralley cars. Plenty of folks have found bad connections at fusible links and bulkhead connectors. I've had bad connections at the battery connectors. So they are all possibilities. At least one guy on the jeep forum found his battery feed wire shorting under the dash (insulation had rubbed off) and several folks have had alternator's short out. These last two generally cause the fusible link to melt, as its supposed to.
 
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