DeLorean will not shut off.

[drdede]

ive been working on a delorean getting it running after sitting, it ran several times and shut off as normal but recently when i went to start it i used a jump starter to boost battery power and now the ignition switch does not shut off the car as normal.

it will start and run and the electrical systems function normally, but now when the ignition switch is turned off most electrical systems(radio, center console) will turn off as normal except for the engine will continue running and the dash lights and instruments still operate despite the ignition being switched off and even the key being removed from the ignition. from there the car must be shut off by removing battery power, the dash and engine will of course shut off and will stay off and when battery power is restored the dash lights will NOT be on with ignition off as one would expect but when the car is started the process will start again.

to sum it up the ignition switch will function normally turning the cars systems on but is not properly shutting the car off, the dash and engine remain powered.

can anyone with better understanding of the delorean electrical system help me fix this problem and lead me into the right direction?
my hypothesis is that the jump starter(50 amp boost supposedly) damaged either the ignition switch or a relay related to the ignition switch

thankyou

[Bitsyncmaster]

One of the AUX relays turns power on and off to the ignition. You may have a bad AUX relay. You can pull fuse #1 to test if that AUX relay still drives power with the key off. If so, pull the control wire off that relay to test if the relay is faulty. It is the AUX relay with the white wires. The other AUX relay has white/blue wires.

[AugustneverEnds]

One of the brown wires in the bundle to the alternator is not supposed to be connected because it causes the car to do exactly what your car is doing. I mistakenly connected that wire on my car some years ago and was very surprised when it didn't respond to the key! I had to kill it by pulling fuse number seven until I discovered the error I made.

[82DMC12]

One of the brown wires in the bundle to the alternator is not supposed to be connected because it causes the car to do exactly what your car is doing. I mistakenly connected that wire on my car some years ago and was very surprised when it didn't respond to the key! I had to kill it by pulling fuse number seven until I discovered the error I made.

Not sure I follow. You're talking about the three brown wires that are crimped together and go onto the B+ post of the alternator? There are two runs of brown wires (three per set). One set goes from the bulkhead stud near the ignition coil to the alternator via the engine harness. Another goes from the starter to the alternator. Both sets can be replaced with 4 gauge copper welding cable.

[Michael]

Not sure I follow. You're talking about the three brown wires that are crimped together and go onto the B+ post of the alternator? There are two runs of brown wires (three per set). One set goes from the bulkhead stud near the ignition coil to the alternator via the engine harness. Another goes from the starter to the alternator. Both sets can be replaced with 4 gauge copper welding cable.

I believe he is talking about the smaller gauge signal wire for the OE alternator which is supposed to be removed altogether if you are using a modern alternator. I think it is in the blue plug on the coil bulkhead and leads to the alternator location. Again it should be just a loose wire.

[AugustneverEnds]

I believe he is talking about the smaller gauge signal wire for the OE alternator which is supposed to be removed altogether if you are using a modern alternator. I think it is in the blue plug on the coil bulkhead and leads to the alternator location. Again it should be just a loose wire.

Bingo, that's the one. I can take a picture of it if someone wants, of course it's not much to look at, after all it's a brown wire like the rest of them.

[DMC-Ron]

Andy,
I think both Nick and Dave are onto something. To assist, I?ve annotated a schematic with the 3 likely scenarios. If, in fact, the smaller gauge brown wire is connected to the two larger gauge brown wires, then that?s your issue. Remove the smaller brown wire from the alternator output and cap it off. It is not needed with a newer style alternator. Other possibilities are a faulty key switch or faulty aux relay.

Ron
69766

[drdede]

thankyou gentlemen.

im going to investigate tonight and see if i can discover the issue.

i do not suspect the alternator wiring is the problem as it was working fine beforehand, i didnt mess with alternator wiring and the alternator is original. i dont know though, the alternator may have been acting up when the car was running.

i will see if i can learn anything tonight and help solve this mystery

[drdede]

when the #1 fuse is pulled he car shuts off immediately.

the duceleir alternator appears to function intermententally, if i rev the engine i can see voltage raise but when running the car breifly just now the voltage dropped from 13 to about 12. when the car was shut off the voltage on the battery read closer to 12.5

this makes me think that the car is drawing power but not producing it, atleast when i was testing voltage while it was idleing.

since yall seem to have targeted the alternator wiring as the likely culprit, and since my ducileer alternator doesnt appear to be functioning properly. this makes me think that my alternator needs replacing. if it is broken that would explain its intermittent function(including battery light illuminating intermittently) as well as the failure for the car to shut off when it should.

time to replace the alternator i would imagine. it seems clear now to me that it must be replaced as thats probably the issue, what do yall think?


on a positive note, the engine behaves so healthy. i am honestly dumbfounded how well it is behaving considering the time period that it sat

[David T]

The "Ducey" alternator is notoriously unreliable. Replacing it is a good idea. Chances are your AUX relay is stuck. Talk to one of the vendors and you probably need the relay upgrade kit and cooling fan relay bypass jumper.

[DMC-Ron]

when the #1 fuse is pulled he car shuts off immediately.

Andy,
Having your battery voltage, settle to 12.5 volts after the engine turns off is pretty normal. If it sets for a few hours, it's not uncommon for the battery voltage to drop to 12.2 or so. Usually with the engine running at reasonable revs, you should see 13.5 to 14 volts at the battery indicating that the alternator is charging. As David notes the duceleir alternator is known to not have enough power and to be flaky. Hopefully, changing the alternator will solve the issue.

Ron

[AugustneverEnds]

Whoa you still have a Ducellier. The only reason I'd keep one of those installed is for a concours museum piece. Knowing that info I'd definitely advise getting a new alternator. Hopefully all of your issues will be resolved in one fell swoop.

[Ron]

Andy,
Having your battery voltage, settle to 12.5 volts after the engine turns off is pretty normal. If it sets for a few hours, it's not uncommon for the battery voltage to drop to 12.2 or so. Usually with the engine running at reasonable revs, you should see 13.5 to 14 volts at the battery indicating that the alternator is charging. As David notes the duceleir alternator is known to not have enough power and to be flaky. Hopefully, changing the alternator will solve the issue.

Ron
+1...but I don't see how the alternator could suddenly start feed the ignition circuit. I think you should follow through with the tests Dave suggested in post 2.

[drdede]

One of the AUX relays turns power on and off to the ignition. You may have a bad AUX relay. You can pull fuse #1 to test if that AUX relay still drives power with the key off. If so, pull the control wire off that relay to test if the relay is faulty. It is the AUX relay with the white wires. The other AUX relay has white/blue wires.

it was the aux relay causing the issue.

problem resolved. thankyou and everyone else who contributed

[Elvis]

please tell us more details. relay sticking ? or melted ? what was it ?