Continues to run when key off and removed

[Carliannewman]

All, looking for some ideas. I searched the archives but couldn’t find this problem.

My ignition (key) stopped springing back after starting.
Before I got smart, it kept the starter engaged until it seized and the gear sheared off the pinion gear in the starter.
When I turned off the key, the engine kept running. I don’t mean for a little bit like run-on or deiseling. I mean it kept running as normal with the key in my hand out of the vehicle.

I pulled the ignition coil wire to stop it.

Forward 1 week later. New starter and brand new ignition installed. Started and runs perfect.
I go to shut it off and take the key, but it continues to run.
I pulled the ignition coil wire to stop it.

I’ve been studying 5he wiring diagram for likely culprits, but thought one of you smart folks would hone right in on the problem. Maybe a secondary failure caused by the ignition switch failure.

[Bitsyncmaster]

Did it always do that? I had an old used car that would do the same thing. That turned out the PO put a wire to turn the fans all the time (engine running) but that also feed power back to the ignition sometimes.

[Carliannewman]

Did it always do that? I had an old used car that would do the same thing. That turned out the PO put a wire to turn the fans all the time (engine running) but that also feed power back to the ignition sometimes.

Very interesting question. My PO does have the fans running the whole time (engine running), but the car never stayed running when I turned off the key. That was new when the old ignition switch failed and when I installed the new switch.

[Jonathan]

What part or parts of the ignition switch did you replace? Perhaps if it is still running without the key in it, you missed the original cause of the problem? I would guess if you replaced the whole metal assembly that wraps around the steering column and into which you stick the key, then the problem is in the round black plastic end that has your wiring connections. That is also the portion that does the springing.

Watch this video and tell me what portion you think might still be your issue: https://www.youtube.com/watch?v=zRVIZO9m1RE

[Carliannewman]

What part or parts of the ignition switch did you replace? Perhaps if it is still running without the key in it, you missed the original cause of the problem? I would guess if you replaced the whole metal assembly that wraps around the steering column and into which you stick the key, then the problem is in the round black plastic end that has your wiring connections. That is also the portion that does the springing.

Watch this video and tell me what portion you think might still be your issue: https://www.youtube.com/watch?v=zRVIZO9m1RE

I replaced just the ignition switch portion. I left the key assembly that is secured to th steering column. My original problem was the key didn’t return to the start position and kept the starter engaged.

[David T]

Stopping the car by pulling the coil wire (I hope you mean one of the little wires to the primary of the coil NOT the big secondary wire!) is not a good way to shut the motor off because you will still have a large draw on the battery unless you also disconnect the battery. Now back to the source of your problems. If the ignition switch is not springing back from the start position to the run position, you MUST figure out why and fix it. Once you get that right you have to make sure the switch portion is working. My guess is something is wrong with it and it isn't electrically shutting off the ignition. If it is working correctly you must figure out where the ignition ECU is continuing to get it's power with the ignition switch turned off. Could be a stuck relay or some creative wiring. Does the car have a burglar alarm? If it does it should be dissected out. This is not a common problem to Deloreans. It will take some troubleshooting to figure out what the problem is.

[DMC5180]

I replaced just the ignition switch portion. I left the key assembly that is secured to th steering column. My original problem was the key didn’t return to the start position and kept the starter engaged.

To clarify, your original issue was that the key did not return (spring back) FROM the start position too the RUN position.

With the New ignition switch installed the engine will not shut off.

Time to start isolating components

Obviously you can kill the engine by pulling the coil wire.

Start the engine again, go to the relay compartment and pull the small white wire off of the Main Relay. This should be the large relay closest to the fuse box and directly behind it. The small white wire is from the ignition switch. If the engine continues to run the relay is stuck closed, (welded contacts). If the engine shuts off its time to look at the ignition switch again. Try this first and report your results before looking at other Possible PO mods.


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[Carliannewman]

Stopping the car by pulling the coil wire (I hope you mean one of the little wires to the primary of the coil NOT the big secondary wire!) is not a good way to shut the motor off because you will still have a large draw on the battery unless you also disconnect the battery. Now back to the source of your problems. If the ignition switch is not springing back from the start position to the run position, you MUST figure out why and fix it. Once you get that right you have to make sure the switch portion is working. My guess is something is wrong with it and it isn't electrically shutting off the ignition. If it is working correctly you must figure out where the ignition ECU is continuing to get it's power with the ignition switch turned off. Could be a stuck relay or some creative wiring. Does the car have a burglar alarm? If it does it should be dissected out. This is not a common problem to Deloreans. It will take some troubleshooting to figure out what the problem is.

Hi Dave, yes the battery was disconnected when I pulled the coil wire.

I replaced the ignition with a brand new one from DMC. I’m certain the PO did some creative wiring.

Yes, something is definitely electrically wrong.

[Carliannewman]

To clarify, your original issue was that the key did not return (spring back) FROM the start position too the RUN position.

With the New ignition switch installed the engine will not shut off.

Time to start isolating components

Obviously you can kill the engine by pulling the coil wire.

Start the engine again, go to the relay compartment and pull the small white wire off of the Main Relay. This should be the large relay closest to the fuse box and directly behind it. The small white wire is from the ignition switch. If the engine continues to run the relay is stuck closed, (welded contacts). If the engine shuts off its time to look at the ignition switch again. Try this first and report your results before looking at other Possible PO mods.


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Thanks Dennis. I will advise.

[Carliannewman]

All, thanks much for the leads. Bitsyncmaster Brought the successful hint.

The PO wired the radiator fan to run whenever the engine is running.

When replacing the starter and cleaning connections/ grounds. I noticed a broken wire from the alternator that I repaired. This wire had been intentionally cut to prevent the fan alteration from running the car without the key but with the fan mod (but I didn’t realize that when fixing).

Now that I know the source I can fix the fans properly the.

The support was much appreciated

A shout out to Josh at DPI who has been very helpful (as always) as well.