Hey Mopar Guru's. This is my first post on this thread. My son has a 74 Plymouth duster w/ a 318. Car starts and runs in start position, but immediately dies when in the run position. We replaced the Ballast Resistor, still had same issue. I bypassed the Ballast by connecting a jump wire, still has same issue. Any ideas on what to try next? should I start checking wires or the ECU, coil??
Car dies in "run" position
- Thread starter Billcode7
- Start date
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mguner
How many is too many?
Ignition switch.
Single or dual ballast?
Dual ballast
Sounds like a bad ignition switch as already stated.
67Dart273
Well-Known Member
You need to determine if the ballast is GETTING power from the switch. While it is not marked as such in the 74 book, the dark blue ignition like coming out of the bulkhead connector and into the engine bay drops from no12 on the pass side to no18 on the engine side. This suggests either a FUSE LINK or a misprint. In any case make sure you are getting power there.
To do that, locate the end of the ballast that is JUMPERED TOGETHER. This is where the power "comes in" to the ballast.
With the key in "run" probe that connection for power, and if nothing, follow the blue wire back to the bulkhead. Probe and wiggle that connection
If you don't have power there, move to the steering column and probe the dark blue wire in the ignition switch connector coming out of the column
IT IS NOT COMPLETELY ACCURATE but you can download a free 73 service manual at MyMopar. That manual, and a few others, came from the guys here
http://www.mymopar.com/index.php?pid=31
http://www.mymopar.com/index.php?pid=109
The wiring diagrams at MyMopar are NOT of Chrysler origin and are NOT completely accurate
http://www.mymopar.com/index.php?pid=28
I have a 74 book which I've scanned and can post sections of it for you.
To do that, locate the end of the ballast that is JUMPERED TOGETHER. This is where the power "comes in" to the ballast.
With the key in "run" probe that connection for power, and if nothing, follow the blue wire back to the bulkhead. Probe and wiggle that connection
If you don't have power there, move to the steering column and probe the dark blue wire in the ignition switch connector coming out of the column
IT IS NOT COMPLETELY ACCURATE but you can download a free 73 service manual at MyMopar. That manual, and a few others, came from the guys here
http://www.mymopar.com/index.php?pid=31
http://www.mymopar.com/index.php?pid=109
The wiring diagrams at MyMopar are NOT of Chrysler origin and are NOT completely accurate
http://www.mymopar.com/index.php?pid=28
I have a 74 book which I've scanned and can post sections of it for you.
Check the ballast resister since you have the dual ballast resister. The 12 volts positive goes into the connection where the ballast is connected together. One ballast has approximately .5 ohms and the other is approximately 1.5 ohms. The engine starts on the .5 ohms when the ignition switch is on "start" and when you turn it loose it goes to run position and runs on the 1.5 ohm side. I bet the ballast is either backwards or the connection from the .5 to the 1.5 side is broken.
67Dart273
Well-Known Member
"Backwards." The original factory connections are polarized to prevent this. If the polarizing key is broken off or the connections aren't original, that could be, but will not prevent the car from running........poorly, probably
So far as the "starts" and "runs" this is not correct. One side of the ballast supplies the coil........exactly as it always has, with points
The other section of the ballast supplies the ECU. This "need" was eliminated in later ECU boxes
The start circuit is somewhat convoluted. The brown from the ignition switch feeds the coil directly. The ECU during start gets power by means of a feedback circuit from the coil + back through the ballast, only during crank.
BillGrissom
Well-Known Member
Sometime around 1974, a seat-belt interlock was part of the ignition and/or starting circuit. It causes many "won't start" issues. Even more than the ignition switch, I would suspect the bulkhead connector since they have many issues (melting, corrosion).
Just "somewhat"?!?!?! LOL
67Dart273
Well-Known Member
The only thing the interlock causes is "no crank." This is easily bypassed at the reset box under the hood. There are two yellow / yellow tracer wires which are the start relay "start" wire. All you need do is permanently splice them together. I intended to mention this, but should not be part of this immediate problem
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