Mopar dies when key is released

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A340

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My 82 Dodge PU was idling in the garage. I heard a small pop/poof and engine died. Looked under the hood, no smoke, no smell, nothing. Go to start it and it starts right up, but as soon as release the key it dies. Right away I'm thinking Ballast Resistor ( 2-pin) I replace it with new. Same problem. Grab my 12v light tester. No power at the coil, no power at the Ballast resistor. Go purchase a new ignition switch ( that's gotta be it!) New Switch, same problem. Take the bulk head apart at the firewall. Look for bad or corroded pins, loose wires, melted wires, etc everything is clean. Get a wiring diagram at this point. Start running wires. So at the solenoid on the fenderwell, red Battery wire feeds the pink wire to the Ballast resistor. Red wire at opposite ends feeds the coil, alternator, carb wire, voltage regulator. I am getting 12v off the red wire only on the solenoid until I turn the key to the start position, at which time it goes to the orange wire that feeds back to the switch. So now I'm thinking it's gotta be the solenoid. New solenoid, no dice, same problem. Looked at all the fusible links and they appear good. Now I can run a wire from my battery to the pink wire coming off the solenoid and everything at that point has 12v. But I shouldn't have to do this.

Answers I received pertaining to this:

1--Is this lean burn? Yes I think it is??

2--Do you have an online line to a good wiring diagram? Yes I do.

Now on the older cars, when the key is in start, the "run" voltage goes "dead" so if something goes wrong between those two, you won't get start voltage at the coil

So double check your light "on the battery" and then see what you get at coil + both in "start" and in "run."

I have power (light) in the start position but none in the run position.


If you for certain don't have voltage in on/ the other/ both, than that's sure a clue.

Some of the newer stuff had a fuse --in at least a portion of-- the switched ignition.

"For test" to see if the ballast/ ECU / etc is OK, you can jumper a clip lead right from the battery (start relay) to coil + and it should start and run. Do NOT leave that hooked up longer than to test.

Yes this is so!
 
have you checked the pickup coil in the distributor and the air gap between the pickup coil and the reluctor.
 
No I haven't. Can't see how or why this would have changed. Engine runs as long as the key is in the start position.
 
I heard a small pop/poof and engine died.

That sure sounds like a fusible link popped. I've had this happen before but I can't remember where the culprit wire was for sure. I'm thinking it was from the starter and the break was right near the starter.
 
I didn't realize it ran in start, re: your PM

What you describe certainly sounds like "typical" bad ballast or loss of "ignition run."

With key in run, engine off, see if you have power on either side of ballast, or coil+, or at blue wire at alternator field. If not, you have a "switched ignition" or "ignition run" power failure, and a fuse/ link would be one thought.

Unless the later pickups have changed, that same buss supplies at the very least, the alternator blue field, the regulator ign terminal, and ignition run, and probably a few other things. The question, then, is "why" did it pop?

Is the wiring ragged? Anything been tapped into it (added?) Had any suspicions, as other odd behavior, intermittent charging system problems?
 
No Power on either side of ballast, or coil+, or at blue wire at alternator field with the key in the RUN position. All the wires are in good shape. Low mileage well taken care of. I pulled on every fusible link I could find to see if it would come apart. Nothing. I agree that it's probably a fusible link at this point. How do I go about testing these other than what I just mentioned. There are f ive them located on the driver side passenger fenderwell. Couldn't see them anywhere else.

On the solenoid on the fenderwell. Should I be getting power on any of the wires connected there other than the RED Battery wire with the key in the run position? When I put the key in the START position power goes to the pink wire that goes directly to the ballast resistor and everything is powered from there.
 
ballast resistor. gets bypassed when you have key all the way over to start.

if it's bad when you release the key -> turns off the car.
 
Sounds like ballast resistor failure to me.
 
I had the same problem and it turned out to be my ECU had taken a dump. slapped a new one on there and has been running great ever since. something to check...
 
could this be his starter relay and the ballast ?
 
I had the same problem on my Dart when i fire up it would start while i had the key in the cranking mode once i release the key it would die out,i thought it was the ignition barrel,replaced and still the same problem so while my son cranked the engine i started to jiggle the wires on that block which is mounted on the fire wall bang fired straight away.Shut her down and remove connectors and cleaned with some brake cleaner and i haven't had any problems since.And before this happened i was driving and it back fired than run for a short period of time than cut out again,i thought it was fuel related the way it was behaving like it had a lack of power and it did this for about 10 k than died out.
 
Have replaced the Ballast Resistor. Still the same problem. Replaced the starter relay,(solenioid) Still same problem. Have taken the bulk head apart checked all wiring and connections, still same problem.

Will check the ECU as a last resort.
 
Have replaced the Ballast Resistor. Still the same problem. Replaced the starter relay,(solenioid) Still same problem. Have taken the bulk head apart checked all wiring and connections, still same problem.

Will check the ECU as a last resort.

Could be the switch (key switch) not sending a signal on the run position maybe
A340.. I don't know what color the wire is that leaves the switch :sign3:
but it could be the switch I would think :glasses7: Good luck and I hope this thread pops up that you found the problem soon..
 
yeah the ign switches can go bad also

there is a write-up somewhere on this forum about how to change it out...
 
First thing i'd do is put an MSD box or HEI unit in it. Eliminate that ballast resistor, a bunch of wiring and that Factory ECU box. You'll be happy you did.
 
First thing i'd do is put an MSD box or HEI unit in it. Eliminate that ballast resistor, a bunch of wiring and that Factory ECU box. You'll be happy you did.

X2 - Just went through same issue, checked all the connections and electrical components. Drove me "NUTS":banghead: Finally did narrow it down to bulkhead connector. The female spade connectors were too loose. Got the wires fixes by drilling bulkhead and splicing wires then I put in the HEI ignition from Trailbeast. No starting problems now and much cleaner engine bay.:cheers::cheers::cheers:
 
Get the test light and your factory service manual out. Find the wiring diagram for the ignition switch out to under the hood. Look in the book and see which wire is hot for the ignition when the key is switched ON. Switch the key on and start probing that wire under the dash on out under the hood and see where you stop getting power. "I" would assume that since it runs in the start position that the fusible link from the starter is GOOD, otherwise there would be no hot signal from the starter. Follow the diagram and probe with the test light. You will find the problem.
 
Get the test light and your factory service manual out. Find the wiring diagram for the ignition switch out to under the hood. Look in the book and see which wire is hot for the ignition when the key is switched ON. Switch the key on and start probing that wire under the dash on out under the hood and see where you stop getting power. "I" would assume that since it runs in the start position that the fusible link from the starter is GOOD, otherwise there would be no hot signal from the starter. Follow the diagram and probe with the test light. You will find the problem.

I could not have said/wrote it better RRR :thumleft:
This is the way to find your lack of 12 volts before removing parts :cheers:
 
Thanks to those that replied. Just to sum up things, if you read my original post you'll see I replaced the Ballast, Ignition Switch, Starter Relay (Solenoid) and took the bulk head apart.

Now here are the questions I need help with at this point.

1. How do you check a fusible link?

2. Should I be getting 12v on any wire other than the Red Battery Wire on the Starter relay when the key is in the "Run" position?

A340
 
Sounds like you have power to the ignition switch and I see you have replaced that.
Are there any fuseable links for the run side you can check or some connector on that side past the fuse link you can use a test probe on to see if power's there.
 
RustyRat: Good call. This is where I was at yesterday. There is a dark Blue wire on the ignition switch that gets changed to Red in the connection on the steering column and harness and later gets connnected to the ballast resistor. That red wire gets its power from the pink wire at the Ballast resistor. This is the one that needs the power, that I am not getting. Now the pink wire is right next to the red Battery wire on the starter relay. I can jump that and restore the power. I thought for sure this was the problem, but after a new solenoid, I still have the problem.
 
I don't know what else to say. Get a wiring diagram and a test light. You'll find it. I promise, proper diagnosis might take time, but it beats throwin parts at it every time.
 
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