I have a 73 340 duster my problem is if i hold the key in the start position it will just crank and not start but if i put the key to the run position really quick it will fire right up. Ive had the car for 12 years and it just started doing this. Any sugestions on where to start looking? thanks.
starting issues
- Thread starter jay dcpt
- Start date
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superchargeddrt
Well-Known Member
Check the ballast resistor or the ignition switch.
Well i had another resistor laying around so i put that on it looked different than the one i originally had on the car. And the car still started the same way and this resistor got real hot and started smoking so im going to bring my original one to the parts store and see it they can match it.
67Dart273
Well-Known Member
Instead of firing blindly in the dark, let's actually find out what the problem is so you can fix it
You need to understand how Mopar ignition switches operate. They are actually SEVERAL switches inside the housing we call the "switch."
ACCESSORY Not our concern for this problem is live in "run" or "acc" feeds power to the acc buss in the fuse panel
IGNITION RUN, also known as IGN1, dark blue, unfused, comes out of the switch, feeds power to the cluster and warning lamps, goes through the bulkhead, and feeds the ignition system, the regulator "I" terminal, and on 70/ later cars, feeds the blue field wire at the alternator, as well as electric choke, if used, and some smog doo dads on some models.
THIS IS HOT ONLY in "run" It is COLD in start. The coil gets voltage from this wire THROUGH the ballast resistor
START YELLOW, hot ONLY in start, feeds power to the start relay to crank the engine
BYPASS, also known as IGN2, brown, THIS IS THE CULPRIT we are worried about in this trouble. This is a separate contact in the switch, feeds power only ONE place -- from the switch, through the bulkhead, to the coil + side of the ballast resistor.
During "crank" the RUN wire is cold, the brown bypass wire should be hot, so if the brown wire has a problem, the car will not fire.
EIther it broke and became unhooked, or the bulkhead connector is corroded, or the IGN switch connector or the switch is bad.
Get access to the IGN switch connector. You may need to remove the small trim under the column
Probe the connector for the brown wire, twist the key to "start" and see if you have power
If you do, the problem is likely a bad connection in the bulkhead connector
If you do not, the switch is bad.
You need to understand how Mopar ignition switches operate. They are actually SEVERAL switches inside the housing we call the "switch."
ACCESSORY Not our concern for this problem is live in "run" or "acc" feeds power to the acc buss in the fuse panel
IGNITION RUN, also known as IGN1, dark blue, unfused, comes out of the switch, feeds power to the cluster and warning lamps, goes through the bulkhead, and feeds the ignition system, the regulator "I" terminal, and on 70/ later cars, feeds the blue field wire at the alternator, as well as electric choke, if used, and some smog doo dads on some models.
THIS IS HOT ONLY in "run" It is COLD in start. The coil gets voltage from this wire THROUGH the ballast resistor
START YELLOW, hot ONLY in start, feeds power to the start relay to crank the engine
BYPASS, also known as IGN2, brown, THIS IS THE CULPRIT we are worried about in this trouble. This is a separate contact in the switch, feeds power only ONE place -- from the switch, through the bulkhead, to the coil + side of the ballast resistor.
During "crank" the RUN wire is cold, the brown bypass wire should be hot, so if the brown wire has a problem, the car will not fire.
EIther it broke and became unhooked, or the bulkhead connector is corroded, or the IGN switch connector or the switch is bad.
Get access to the IGN switch connector. You may need to remove the small trim under the column
Probe the connector for the brown wire, twist the key to "start" and see if you have power
If you do, the problem is likely a bad connection in the bulkhead connector
If you do not, the switch is bad.
green1
Well-Known Member
It's the switch.
Funny I find this post here. I have the exact same problem that you have and I'm in the process of troubleshooting it also. We need to stay in communication and see who finds the problem first. My car is a 1970 340 Duster. You might want to follow my posting labeled "Overcharging Issue and Car Starting Issue". I also have an overcharging issue I'm troubleshooting but along with it my car starting doing the same as yours if I hold the key in the start position it will just crank and not start but if i put the key to the run position really quick it will fire right up. Strange !!
67Dart273
Well-Known Member
I think since you have an MSD, now that we know that, your problem is a little different
Check to see if you get these readings on your car. I got them on mine. I'd be curious to see if you read the same on yours !
I disconnected my ignition connector on the steering column from the main wiring harness. I place the ignition switch to the 2nd click (Run position)
Taking a volt ohm meter to make make some continuity checks I made measurement from the Red wire to the IGN1 (Blue) and had no continuity. The new cable showed continuity.
Taking a volt ohm meter to make make some continuity checks I made measurement from the Red wire to the IGN2 (Brown) and had continuity. The new cable showed no continuity.
I think that this is the reason that your car will not start when the key position is placed to start but will start when the key position comes back to run (IGN1)
I disconnected my ignition connector on the steering column from the main wiring harness. I place the ignition switch to the 2nd click (Run position)
Taking a volt ohm meter to make make some continuity checks I made measurement from the Red wire to the IGN1 (Blue) and had no continuity. The new cable showed continuity.
Taking a volt ohm meter to make make some continuity checks I made measurement from the Red wire to the IGN2 (Brown) and had continuity. The new cable showed no continuity.
I think that this is the reason that your car will not start when the key position is placed to start but will start when the key position comes back to run (IGN1)
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