motor keeps running after ignition switch is turned off

-
CDA1967NBK

CDA1967NBK

Member
Joined
Nov 24, 2013
Messages
15
Reaction score
4
Location
Rochester New York
Hello folks

Any ideas why a 360 would keep running on my friends 1973 Duster even with the ignition switch off? Runs fine but he has to pull the coil to stop the engine.

Replaced ignition switch in the column, checked amperage off battery and it is drawing 8 amps in the key off position.

Starter relay?

Thanks in advance!
 
Does it stop when in gear? Dieseling? If so, not enough initial timing is my guess.

If it keeps running because the ignition is still hot... better start looking at the harness for a problem. I'd check the coil positive side with a test light to see if it goes dark when key is turned off.
 
Have you made any wiring changes "not factory"

As Crackedback said above^^ check to see that the coil is actually getting power

If no wiring changes have been made, start the car, reach down and unplug the column connector for the ignition switch. If the engine dies, you have a bad switch. AbodyJoe wrote a great "how to" on "how to" change the switch
 
67Dart273 said:
Have you made any wiring changes "not factory"

As Crackedback said above^^ check to see that the coil is actually getting power

If no wiring changes have been made, start the car, reach down and unplug the column connector for the ignition switch. If the engine dies, you have a bad switch. AbodyJoe wrote a great "how to" on "how to" change the switch
Click to expand...
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Sound like the ignition is not switched and full time hot. I for one do not enjoy having to pull the coil wire!
 
Had enough bleed thru on my new solid state Chinese regulator to run my msd ignition. Stopped when I replaced it with a mechanical regulator.
 
crackedback said:
Does it stop when in gear? Dieseling? If so, not enough initial timing is my guess.

If it keeps running because the ignition is still hot... better start looking at the harness for a problem. I'd check the coil positive side with a test light to see if it goes dark when key is turned off.
Click to expand...

So the lite stays on all the time on the positive of the coil even turning the key on or off. Timing is perfect.
 
67Dart273 said:
Have you made any wiring changes "not factory"

As Crackedback said above^^ check to see that the coil is actually getting power

If no wiring changes have been made, start the car, reach down and unplug the column connector for the ignition switch. If the engine dies, you have a bad switch. AbodyJoe wrote a great "how to" on "how to" change the switch
Click to expand...
Yes it has an aftermarket harness but has been running fine for over a year. Switch is now replaced and doing the same thing.

Many thanks
 
OK what else is branched off the "ignition run" line Seems to me there was talk of isolation diode with MSD and some charging systems. What do you have for an alternator/ regulator?
 
CDA1967NBK said:
Alternator was replaced last year. Checking that next.

Thanks!
Click to expand...

No I mean "what" (kind) are you running? What VR? 69/ earlier Mopar? 70/ later Mopar? Delco/ Denso "what?" or "one wire?"
 
Did you check the coil+ power with engine running or stopped?
 
67Dart273 said:
No I mean "what" (kind) are you running? What VR? 69/ earlier Mopar? 70/ later Mopar? Delco/ Denso "what?" or "one wire?"
Click to expand...
Two fields.
When it is running the light is bright off the positive coil.
With the car off the lite tester is dimmer but still lite off coil positive.
See attached photo of alternator. Was replaced last year and ran fine all year. 1973 Duster.

IMG_6403.jpg
 
Looks like stock type harnessing. Pull the ignition switch plug and find the bleed over. Something is bad or there is something tied on ignition run circuit in a way it should not be. I assume a three wire VR.
 
Well you need to determine if it's the ignition switch or some "feed back" from something else getting "back" into that circuit. You can disconnect the ignition switch at the connector and "ohm it out" or use a test light and battery. That is the FIRST thing I'd do

The 73 shop manual is for free at MyMopar, and it CAME from some of the guys right here. There IS a mistake on that diagram (misleading) it shows the IGN2 coil bypass circuit coming off the same switch contact as the start relay wire which is NOT the case
 
Right out of the book

#12 RED is main power coming in NOT FUSED!!!

Large BLACK is ACCESSORY power out to the fuse panel acc buss

#12 Dark BLue is the ignition power out to electronic ignition, alternator field, VR, some smog devices

As I said the yellow and brown ARE NOT connected as shown. The brown (went) to the coil side of the resistor, if you have MSD it should have been jumpered to the dark blue. That wire (brown) is ONLY hot when cranking and the dark blue goes DEAD when cranking

The yellow of course is the "start" wire goes out to the start relay

ignA.jpg


ignB.jpg
 
WHEN IN START:

You should have continuity from red to yellow and from red to brown

WHEN IN RUN

You should have continuity from red to dark blue and from red to black

WHEN IN ACCESSORY You should have continuity from red to black
 
CDA1967NBK said:
Yes it has an aftermarket harness but has been running fine for over a year. Switch is now replaced and doing the same thing.

Many thanks
Click to expand...
Many thanks!! Problem resolved and lesson learned by my buddy. Had a "Mechanic" fix a tail light problem and low and behold he fed the taillight with the ignition harness. New harness and replace broken trunk wire which was the original issueand problem resolved.

Many thanks for allthe help!
 
You must log in or register to reply here.
-

Back
Top