Like the title states, my 73 2.0 will not shut off. Originally I assumed the problem to be the ignition switch, so I have been temporarily pulling the green coil wire to shut her down. Now, after putting in the new ignition switch (from Pelican), the car exhibits the same problem. Any leads on where to start? Also, the old switch looked just fine, no major wear and tear, argg!

Start at the coil. Put your voltmeter on the +V side of the coil and turn the key on and off. Power should be +12V, then 0V.

Follow the wire diagram from the coil to the ignition switch. make sure all wires are intact with good insulation.

Sorry, I don't have a silver bullet fix. Start at the load (coil) and work your way back to the switch. Somewhere you should see +12V then 0V.

unplug the alternator lead to the replay board.

Keep the old ignition switch. The PP ignition switch I bought broke in about 10 starts.

I agree on the wiring to the coil. If the coil gets a solid 12v then it'll keep the engine running till it doesnt get those 12v any longer.

odd but true.
Remove your taillight bulbs,,,,see if it keeps happening.
Wrong bulb back there can keep the car running...single filament versus a dual filament.

With that said...a shorted out socket could also do it...so remove the bulbs.

Rich

alright, so the car still wont shut off after having no bulbs in at all. I don't have a voltmeter right now (most of my tools are in storage), so I will rig up a test light to check the coil. Watching my future stepdaughter today, so I am working in between naps. Granted, it is quite obvious the coil is getting power when off.

You know you have 12volts at the coil because you are shutting it down by removing the 12volts. So forget that.

Edit: Maybe a bad relay board? CHeck for 12v at T-14-8. Then turn the key off and check for power at T-12-7.

i've not only experianced weird things happening with the incorrect tail light bulb installed but heard of many strange issues related. let us know

Jared ... Do what George says and disconnect the alternator and see if that is the problem feeding back into the ignition circuit. Never thought of that.

Ran out for a minute and unplugged the alternator. Changed nothing, car still wont shut off.

Do you have a MSD ignition system, if you do you need the diode installed per
there instructions.

Pull fuse #9 and try it.

Get the volt meter and some sewing pins.
In front or behind the shifter, on the tunnel, is the large bundle of wires that go up the the dash.

You are looking for two or three fat red ones and a fat yellow one.
Stick a sewing pin through the middle of each one being careful to not allow the pins to touch ground.

test each wire for power with the car off.
You should find one with power, the main feed from the battery to the fusebox/ignition switch.

Turn key to run, test each wire for power.
You should now find two with power...on going fowards (same as the last test) and one going back to the relay board.

Turn key to start, you should find three with power, two reds and a yellow (may have a stripe, cant recall)
Fat yellow is the starter trigger wire.

Turn key off.
You should once again only see power on one fat red wire.
If you see power on more than one of the red ones, pull your ignition switch out, unplug it and see if you still see power on more than one wire with the car not running.

This is to try and isolate the ignition switch as the culprit.
If you still see power on two wires, you may have your fuse box wired incorrectly, or you may be back feeding from the engine bay...

So, try those test and let us know.
If you are backfeeding, you need to unplug the relay board and test again....then unplug the alternator and test again.

If you are feeding from the fuse panel, pull it down, take a pic or two of the back and if you have really clear pics, we can probably see the error.

Rich

Thank you Towle, I will borrow a voltmeter from my Gf's dad today to figure out the culprit. I did try removing the #9 fuse, no change. The only way the car would shut off by the key is if both the alt and starter is unplugged from the relay board. (The starter is the 10+ pin one next to the alt right?) Thanks guys, I will try poking with a voltmeter and get you guys a photo of the fuse panel ASAP.

-Jared

try to think about what I proposed above.
It will isolate the issue to either the engine bay or the dashboard.
That is the first step...figure out which direction to head towards to diagnose it.

From there, we can talk about a few tests on the in and out from the relay board to see if that board is the culprit or we can look at the fuse panel (backside) to see if that is the issue.

I would suggest that you think back...
If it did not do this before, and you replaced something, then it started to do this....go back and look at what you replaced first...could be a simple thing.

Rich

Just for giggles, try unplugging the cold start injector. I had weird things happen on my 73 if it was plugged in. Probably not it, but easy to check.

You forgot to mention the voodoo doll and the blood of a newt.

You said you replaced the Ign switch. Did you also replace the white plastic plug on the end of the switch? Don't know if that will cause your problem but mine had a hairline crack and caused crazy starting problems until I replaced it. Good Luck.

What kind of electrical work have you done lately? A hot wire has grounded somewhere and made a loop in your system, it happened on my 928 one time. retrace what you have done.

then is has to be the ignition switch or a melted wire.

Stop putting gas in it. It'll stop

I just noticed, you said your pulling the green wire? The one from the points? Could it be possible things are hooked up wrong on that coil?, like the tach wire mixed up or the points on the wrong terminal? Take a pic and post it.

Jeff, I owned the car. I told Jared to pull the + wire off the coil.

I let the car sit for a period of time (a few months). Hooked a battery charger to it and started it to move it. When I went to shut it off with the key, it wouldn't. I didn't bother trying to trace it down at the time.

When asked I told Jared I didn't know the reason, but it might be the ignition switch. I assume a wire is grounded against a hot lead from the battery or voltage is feeding back thru the wiring.

John suggested pulling fuse #9. Pulling that one should disable power to the coil.

Got it. For sure post a pic then

You've had lots of good advice so you are on your way to the solution. Another idea might be to hook up the voltmeter inbetween the positive cable and the battery with the ign sw off and it probably will show a 12v drain. Without sttarting the car just start taking red wires loose at their terminals one at a time and watching the meter. When the 12v drain goes away you have found the source of the voltage supply. I guess this will also work on the coil supply wire with the battery still hooked up.

Rich's path is good but a little more dissassembly will be required.

Okay, so I did a few tests with a test light.

But the gist of it all is, the two red wires for the ignition both have power always.
Also, with the ignition switch unplugged, there is still power to both of the red wires.
These tests were performed on the harness between the shifter / firewall.

After unplugging the ignition switch, I tested for power at that plug. One had juice, the other did not. Yet they both have power around the shifter?? My assumption is that one of the "reds" is getting power via grounding against a hot wire somewhere around the fuse panel or under the dash?

Attached are two pictures of my fuse panel, front and back.

ooops, ignore this post.

New update, problem is in the rear of the car, I clipped all three wires, two red and one yellow, while the car was running. I did my cuts behind the shifter, so the problem is likely to not be related to the fuse panel / under-dash wiring.

PS: Yes I know that was ghetto, I was trying to make a temp fix to get the car mobile and off my street by using a switch to shut off the power down there. My thought was that if I killed a wire there, the car would die? No dice.

Could one of the two large plastic connectors on the relay board be off by one pin?
It would be worth a try to remove both and put them back on ...

Post some pics of the relay board and engine bay!

Your car wasn't by chance struck by lightning, was it?


https://www.youtube.com/watch?v=WjeptaI2T8E

Did you change the main relay on the relay panel? This is the one nearest the fuses. It could be a sticking relay.

Okay, reconnected my cut wiring on the tunnel. Here is a pic of my relay board. Checked the pins on the board and everything checked out okay. Followed the harness around the engine bay and didn't see any exposed wiring that could be grounding out. FYI, I removed the voltage regulator to better show the board, sorry for the Sirandy quality photo.

big plug in the back....pull it and test to find power.
Closest to the firewall...the main feed for the relay board.

Find the power first...then work backwards, you may have missed one wire in the tunnel.
I will go look later tonight to give you a better idea of the wires you are looking for...

RIch

how many smaller red wires are connected to your batter positive terminal?

Rich

Four! Thanks Rich!

PS, maybe this is why I always ran carbs on my old car....

Give me an hour or so, I will go chase all of them...

It should be a simple thing to figure out...I have a stripped out car here.
Carbs or not...same wires are there...

Rich

The one thing I was wondering about was the starter solenoid connection. How 'bout the big yellow wire feeding back into the circuit if the solenoid is screwed up?

I know that some have an extra spade terminal and (as I remember) it is a "run" connection in that it has power from the battery.

I guess you could start the car and pull the yellow wire off the spade terminal and then shut the car off with the key as a test.

Oh well, just a guess .......

while your in there, clean that ground connention on the stud/nut. i see green on that vacant relay plug. what's it look like under the other 3 relays. got any green growth between terminals? did you brush your teeth? nag, nag, nag.

So, are you saying that by clipping a red wire you were able to get the car to stop running?

I believe that your coil still must have power with the ignition switch off.

The power is the BLACK wire connected to the coil. The green wire on the coil is actually a switched ground wire from the ignition breaker points.

I would venture to guess that if you had fuse 9 removed, you have eliminated the coil being fed current somehow from the brake lights or switch.

I believe that somewhere along your harness, you have a short to some hot with the black coil wire.

I have forgotten, is this a 73 or 74 car? If it is a 74, check the interlock over-ride relays under the passenger seat. This may have been "modified" over the years. It would prevent the car from starting if the seat belts were not fastened. Over many years, when this item was deemed to be a problem, many people disabled the device.

If done incorrectly, one of the black wires may be shorted to hot in this spot.

This car still runs with the two large red wires and the yellow one CUT behind the shifter. No power is coming from the ignition wiring from the firewall and forward. Also, the car still runs even if the #9 nine fuse is removed. Lastly, I drove it to the gas station to fill it up (she was nearly empty) and the #9 fuse blew, killing the tach and all the accessories. Strangely though, the car keeps running. If this car was carbed, I would just install a painless wiring kit, that makes sense to me, lol. I will check the aforementioned wiring under the passenger seat in the morning.

Thank you guys for all your input so far, the vast knowledge of the members of this club never ceases to amaze me.

I suppose that there could be something wrong with your relay board (engine comp).


If your wiring is stock, I would check the wires on the coil. One side should have a black wire (hot {12 v} with the ignition switch on). The other side should have two wires: green (switched ground from ignition points), Black/violet (signal for tachometer).

If the car is a 1973 or earlier, there should be no relays under the passenger seat

well, I am going to hit up the locals for a relay board. This whole situation has been quite frustrating. I will replace the board and then just go from there. I am considering pulling the whole body wiring harness and replacing every damaged / burnt connector that I can find.

come and get a couple ............

Actually, PM me your address and I will send a couple your way.

I suppose you could unplug the relay board and see if it still runs then.....

Have you checked over your coil wiring?

It might help if you post a picture or two.