1970 Dart Electrical issue

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Blue man

Blue man

Blue Dart
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Jun 12, 2016
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Crosby, Txeas
Old school, looking for answer on my 70 Dart, electrical issue.. I started out on a drive the other day 20 min from the house. I stop at the store got back in to start the engine turned over and would not start. It puffed smoke out the carb and acted like it wanted to crank just as you released the key switch. I check for fire on number one and at the coil, ck the rotor to make sure it looked okay. Again, it would turn over but would not crank like it is not firing. A young man with a trailer was driving by and stop to look at my Dart. I told him the problem so we loaded it up an took it to my house. Rolling off the trailer in neutral I hit the ignition switch an the car crank up I was simply dumb founded. So, I waited a while contemplating to continue my road trip...so I did.

When on a cruse hung for a couple of hours then headed home and it did it again. Cranking over engine, the puff of smoke would not start. I sit for a few minutes then it cranked up. Got home a started checking the under the hood wiring harness. Ck the bulk head, with it running the blue fusible link was to hot to the touch it would burn you.

The wiring harness is 7 to 10 years. I replaced All the under hood wiring harnesses. It is running now, looking for answer why it did what it did. Also, new ignition switch, turn signal, new dash cluster. Like I said I restored a few years ago all the gauges are working properly the horn did honk a couple of times without pushing the button.

Thanks for reading my small short story. This one got me stumped
Can any one help.
 
Is the car using electronic ign. or points ign?

I had a similar situation with a Cordoba I had years ago. Turned out to be a bad pickup in the distributor (elec. ignition of course). Didn't know how to replace the pickup back then so I put in a new distributor and bingo it was fixed.

The thing where it sounds like it is going to start just as you stop cranking is caused by something else, and it eludes me right now but one of these smart fellers will chime in as to what causes it.

Best,

CE
 
What do you mean by the 'blue fusible link'? Is this between the starter relay's big lug and the connector, or is this the blue wire running to the ballast?

Firing just as you release the key from START to RUN could mean that the ballast bypass wire is having an issue. That is the brown wire that goes to the same end of the ballast resistor as the wire from coil +.

Get a voltmeter or 12v test light and check for 10 volts or so at the end of that brown wire where is connects to the ballast while cranking. If not, then the wiring to that point has a problem or the ignition switch has a problem.

If the fusible link is indeed hot, then check the connector at the firewall for heating and corrosion.
 
Determine if this is fuel or ignition.

Check for spark when cranking USING THE KEY. Get yourself a parts store spark checker "gap" or otherwise "rig" something you can see when twisting the key. You can rig it up and look under the hood gap.

If no spark, put the key into "run" and check again for spark using a metallic object to jumper across the starter relay.

If no spark......get your meter or minimally, a 12V test lamp. "Rig" it to the coil POS terminal. With the key in run, check power. You should get LESS than battery, somewhere around 6--9V.

If you get "full battery" power, check the coil NEG terminal. It should read quite low, about a volt. If it's "high" near battery voltage VERY first thing to check is whether the ECU is GROUNDED

Somewhere on this board I posted up a test procedure for Mopar ignition
 
ValiantOne said:
Is the car using electronic ign. or points ign?

I had a similar situation with a Cordoba I had years ago. Turned out to be a bad pickup in the distributor (elec. ignition of course). Didn't know how to replace the pickup back then so I put in a new distributor and bingo it was fixed.

The thing where it sounds like it is going to start just as you stop cranking is caused by something else, and it eludes me right now but one of these smart fellers will chime in as to what causes it.

Best,

CE
Click to expand...
 
The ignition is all aftermarket 6Al spark box, dist and a Mallory coil. The blue fusible link in at the fire wall in the center bulkhead. Is the link suppose to get super hot.

Guys, the car is running great in the garage. This car ran perfect before this incident. I replaced rebuilt the whole car except the paint and headliner. Oh the under dash wiring is still original this car has AC it gets hot in Texas...lol
 
Blue man said:
Old school, looking for answer on my 70 Dart, electrical issue.. I started out on a drive the other day 20 min from the house. I stop at the store got back in to start the engine turned over and would not start. It puffed smoke out the carb and acted like it wanted to crank just as you released the key switch. I check for fire on number one and at the coil, ck the rotor to make sure it looked okay. Again, it would turn over but would not crank like it is not firing. A young man with a trailer was driving by and stop to look at my Dart. I told him the problem so we loaded it up an took it to my house. Rolling off the trailer in neutral I hit the ignition switch an the car crank up I was simply dumb founded. So, I waited a while contemplating to continue my road trip...so I did.

When on a cruse hung for a couple of hours then headed home and it did it again. Cranking over engine, the puff of smoke would not start. I sit for a few minutes then it cranked up. Got home a started checking the under the hood wiring harness. Ck the bulk head, with it running the blue fusible link was to hot to the touch it would burn you.

The wiring harness is 7 to 10 years. I replaced All the under hood wiring harnesses. It is running now, looking for answer why it did what it did. Also, new ignition switch, turn signal, new dash cluster. Like I said I restored a few years ago all the gauges are working properly the horn did honk a couple of times without pushing the button.

Thanks for reading my small short story. This one got me stumped
Can any one help.
Click to expand...
 
Thanks to All, who replied so far... The MAD wiring article might just do the trick. It is just weird after all these years an electrical gremlin appears. Why not put a volt gauge to replace the Amp one?
Couldn't sleep
 
Blue man said:
Thanks to All, who replied so far... The MAD wiring article might just do the trick. It is just weird after all these years an electrical gremlin appears. Why not put a volt gauge to replace the Amp one?
Couldn't sleep
Click to expand...

You can do that. This old thread, read it all.......

Ammeter to Voltmeter...who does it?

The "improved" software makes these old threads a huge PITA. But if you click on individual links you can pop them up
 
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