Ratt Dawg Ralph

Okay, before you say Ballast Resistor or Ignition Cylinder, read my post first! I've got a 1967 Dodge A100 Van with a 225 Slant 6 & 727 Trans. To start off from the beginning, I just did an engine swap on the van and the van ran perfectly fine before the swap. Reason for the engine swap was, it needed a valve job and I found a newly rebuilt one for cheap. So I swap the engine put everything back where its supposed to go. Started the engine, tweaked the timing and it starts right up and idles good. I started it everyday while still working on other stuff (brakes, etc.). So, one day I go out and start it up and I turn the key, it starts but when I let go of the key engine dies "fast". If I leave the key turned all the way it will run smoothly but starter is still engaged. Carburetor is getting gas too. First off, the person who owned this van before me did a bunch of modifications to it with later parts. Its got an ignition module from a 72 Dart, which didn't come in the 67 vans and a voltage regulator also out of a 72 Dart. And other silly mods, which were just silly!
So first off, I did my research and I replaced the ignition cylinder and no luck! Then I bought a ballast resistor for a 72 Dart, and no luck! Then I bought the ignition module for the 72 Dart, and no luck! Keep in mind that all these 72 Dart parts are exactly the same as the old parts that are being replaced and the van ran fine before hand. Then I bought a new starter relay and no luck! Took the starter off and had it checked out and it was good. I also replace the voltage regulator, just because, and no luck! Checked all the wiring for fried wires or bad connections and they all looked good!
So, I'm stuck and don't know what to do! I'm kind thinking its the ignition. I don't have an volt meter, but I can buy one if needed!
Any suggestions?

Coronet 500

The first thing I would do is take a voltmeter (multimeter) and see voltage at coil + in start then run (on). Then the incoming side of the ballast resistor with the same procedure, just to see what voltage you are getting from the ignition switch. This should give good information to help with the diagnosis.

Crazy4Carz.Com

There are two electrical circuits, one for "start" and one for "run". The one for start is fine, the run circuit is bad. Just because you changed parts, that doesn't mean the part is good! First thing you need to do is get a meter and be sure the parts you have changed are good and the old ones were bad. Obviously if you changed a bad part with another bad part the problem is still there.

Don't be a parts changer, diagnose the problem first then repair it once. A cheap functional meter is less than ten bucks at radio shack. (less than you spent on any one part so far)

Good luck, be sure to come back and let us know the progress.

440roadrunner

First two answers are both on the right track.

FIRST thing you MUST do is obtain a wiring diagram, or better yet, a factory shop manual. You should be able to find one on ebag

ALL these old girls are having troubles with original wiring AND THE BULKHEAD CONNECTOR which was never designed to handle high charging current.

Here's how Mopar basic ignition works:

The ignition SWITCH has several separate switch circuits within

ACCESSORY hot either in "run" or "accessory" feeds power to the fuse panel for the accessories

IGNITION RUN sometimes called ign1, is hot only in run, is traditionally dark blue, and feeds power OUT THROUGH THE BULKHEAD and to the high side of the ballast resistor

START traditionally yellow, is hot in "start" and engages the starter relay on a stick, or engages the relay on an auto if the shifter is in park or neutral GOES THROUGH BULKHEAD

IGNITION BYPASS traditionally brown, also hot only in "start" and feeds power to coil side of ballast resistor and GOES THROUGH BULKHEAD

So far as the "dark blue" ignition run circuit, you have several opportunities for voltage drop, the most suspect being the BULKHEAD CONNECTOR, the connector on the rear of the ignition switch, and the ignition switch itself, NOT the lock cylinder

Put the ignition key in "run" measure battery voltage at the battery, and measure voltage at the ballast resistor. One side should be fairly low, 4-6V showing the "box" (ECU) is drawing current through the resistor. The other side should be VERY close to battery. I'm guessing either it is not, or that you still have a bad ballast resistor, even though you replaced it, OR those connectors are screwed up

If you do NOT have voltage present, it's a tossup: Either pull apart the bulkhead connector and inspect, or pull out the ignition switch where you can get to the rear of the connector, and check voltage there

IF YOU pull the bulkhead apart, and "get" voltage on the interior half, DO NOT ASSUME that it's OK. When you measure voltage with a meter or SMALL test lamp, these do NOT load the circuit very much. You could have a bad switch, and still measure OK with no load on the circuit. One good way of "getting around" this is to make up a "heavy" test lamp. I use an old stop/ tail socket, and wire up so BOTH filaments can be lit if I want---I just use a wire nut to hook them up.

This "heavy" test lamp will LOAD the circuit, and if there's a bad connection, it will usually "arc" and lose connection. Do NOT be afraid to give things the "wiggle" test. Very often bad connections can be found this way.

The following WILL NOT explain this problem, but BE AWARE:

If you have a 2 terminal ballast resistor, you MUST USE the newer so called "4 terminal" ignition box (ECU)

If you have the older 4 terminal ballast, you can use EITHER the newer 4 terminal ECU or the older 5 terminal ECU

YOU CAN NOT TELL by looking. Many "4 pin" ECUs still have 5 pins, it's just that the 5th pin is not connected.

To bad you "threw parts" at the problem. You probably did not need anything you mentioned replaced.

Ratt Dawg Ralph

Thanks for the help everybody! First off, I am not a mechanic and was actually surprised that my engine swap I did all by myself was a success. I can do the basic R&R (Remove and Replace), but I have no idea when it come to diagnosing problems. That's where my part buying frenzy came in.

Whelp, I solved my problem. When I did my engine swap, I replaced a few old cracked lines in the harness. I didn't replace the whole line like I should have and I just cut out the bad part of the line and put in a new one. All the lines are where they are supposed to be and nothing is out of place. On my cheap quick fix wiring job, the wire that goes from the ignition to the ballast didn't have a good connection between the old wire and the new one I put in. So I replaced the deal that connects the two and wallah, it started right up. I need to go back and replace the lines as a whole in the harness. But its good and running now.

But, of course a new problem arises. Overheating! The radiator looked good inside, no corrosion or rust. Heater core was replaced because it sounded like a tambourine when I shook it. The water lines to the heater core were clogged, but now cleaned out. The temperature gets high while idling. Gonna start off with a new thermostat and see how that goes.

Coronet 500

Good job. Don't worry about the parts, you got some experience and you've got some spares you know should be good for any future problems.
When you start leave the rad cap off so when the thermostat opens it should burp any air out.
I really dig your Mopar Party Wagon.

samuelcosmo76

if the van's a rockin.....hahah

dig it

TVLynn

Had a 67 A100 many years ago. Had an Electrical fire in the McDonald's parking lot. She quit & I opened the engine cover to see the wiring cooking. Kept yanking on the battery cable until it broke. End of smoke. Main alt wire shorted to motor. Just needed some wires So make sure the alt wires are secure and there is nothing wrong with the upgrade to 72 parts