truck runs when I turn the key off - - The 1947 - Present Chevrolet & GMC Truck Message Board Network

dan42 · 10-10-2009, 08:50 PM

I just replaced the tumblers 6 months ago, but this afternoon I tried to turn the key of and it kept running. is the switch bad, or is it possible I lost a ground, because I am in the process of taking my bed out? I'm not crazy about having to disconnect the battery to turn the truck off every time.

dan42 · 10-10-2009, 09:29 PM

I just took the ground side of the battery off and it kept running. I've never done that before (there was no reason too) but does anyone know if that's normal?

**LockDoc** · 10-10-2009, 09:38 PM

The switch could be bad or it could be a short. I don't think it has anything to do with the bed. Does it have an HEI distributor?

It's probably running off of the Alt.

LockDoc

jay6891 · 10-10-2009, 10:13 PM

I had a 71 burb, and I know this sounds crazy. Would keep running with the key off if the radio was turned off. Turn the radio on and the key off, engine would die. Never did figure that one out.

Pont406 · 10-10-2009, 10:23 PM

My truck and cars did that also after installing msd boxes. There is a diode you can install in the alt wiring so it stops backfeeding voltage.

dan42 · 10-10-2009, 11:17 PM

It does have a HEI, but it's been on the truck for over a year with no problems until today. I think I'll start at replacing the switch.

Longhorn Man · 10-10-2009, 11:38 PM

do you have an electric fan by chance?

dan42 · 10-11-2009, 02:37 AM

No electric fan. I tapped the switch a couple of times, thinking maybe something stuck, but nothing. I do have an amp and radio installed but it has worked fine for maybe 3 or 4 months with it until now.

72freak · 10-11-2009, 05:27 AM

Unhook the wiring hartness from the key switch and see if its still running.

redneck-chevs · 10-11-2009, 06:22 AM

Quote:

Originally Posted by dan42

I just replaced the tumblers 6 months ago, but this afternoon I tried to turn the key of and it kept running. is the switch bad, or is it possible I lost a ground, because I am in the process of taking my bed out? I'm not crazy about having to disconnect the battery to turn the truck off every time.

I would say the ingnition switch is bad the contacts inside prolly broke the easiest way to shut the truck off is to pull your main ignition lead off of the distributor but that will be a pain to do that all the time good luck

**LockDoc** · 10-11-2009, 08:00 AM

-
After reading through this again I think Pont406 might be on to something. Try unhooking the wiring to the alternator, start it up and see if it will shut off. Make sure the alt. wires aren't touching anything metal.

LockDoc

toddtheodd · 10-11-2009, 08:22 AM

It's just how great these trucks are. Nothing can kill them. They run no matter what... Even when you try to kill them, they keep running... You can't even turn these bad boys off.

SevenOne · 10-11-2009, 09:27 AM

Quote:

Originally Posted by toddtheodd

It's just how great these trucks are. Nothing can kill them. They run no matter what... Even when you try to kill them, they keep running... You can't even turn these bad boys off.

funny chit

dan42 · 10-15-2009, 11:24 PM

O.K. - I pulled the alternator wire off, and tried to turn off the truck - no dice. I have now replaced the ignition switch with a new one from Brother's, and it still doesn't shut off. Does anyone have any good ideas??

**LockDoc** · 10-15-2009, 11:43 PM

-
Is there only one wire that plugs into the HEI?

Where does the hot wire to the HEI come from?

Unplug the hot wire from the Distributor and see if it is hot with the key off. If it is you have it hooked to the wrong source.

LockDoc

vectorit · 10-16-2009, 12:05 AM

I'm real interested to see the culprit to this gremlin.

Since years ago, before I began restoring my burb I had the same thing happen to me. Just so happens I was stuck up there in your neck of the woods!

Luckily I was up at my Mom's house, and I had a local Napa store near by.

The only way I could get mine to stop running was to through a rag on top of the carb to choke out! I had disco'd everything as well, and it would just keep running.

There was a bigger problem though. In my case I could not get the truck to go above 3K RPM under load, if I did it would sputter and backfire... Long story short, I ended up going home with a borrowed car. Once there I grabbed a engine I had, and trucked it up there. Had the local Chevron swap out the motors, then drove it home!

Took my 327 to the shop for a diagnosis, and apparently all of the rings washed out. Half were broken, and the others were pollished and the edges rounded off. I would have never believed it, but the machinist showed it all to me. He said that I must have over heated or leaned it out?
It was a hot day, and I did hot dog it up highway 101 up the steep grades but I know I didn't overheat...

One of my all time mystery's I have had in my burbs past.

dan42 · 10-16-2009, 12:18 AM

Quote:

Originally Posted by LockDoc

-
Is there only one wire that plugs into the HEI?

Where does the hot wire to the HEI come from?

Unplug the hot wire from the Distributor and see if it is hot with the key off. If it is you have it hooked to the wrong source.

LockDoc

I will check that out - but why would it have run for basically the last year, and I haven't changed anything?

white 67 · 10-16-2009, 12:43 AM

Mine did that when there was a problem with the alternator wiring. I would try another new switch, i had a hard time with my wipers last year becuase i got a bad switch from brothers. I replaced the switch then the motor and then found out my new switch was bad.

fixit-p · 10-16-2009, 01:35 AM

I would go with locdocs recomendation to test with key off engine off if there is power at the batt terminal on the hei (If there is no power it suggests feed back on the alternator wiring brown wire) If there is power with koeo it a wiring or switch issue.
Do you have external or internal voltage reg?

dan42 · 10-16-2009, 09:37 AM

Internal. 1 wire alternator. It's actually the second switch I got from Brother's - the first I couldn't even get the tumbler installed into. This one had a big chunk of plastic on the bottom of it I had to fish out before I could install it.

UltraBlue71 · 10-16-2009, 10:02 AM

I'd be a little more concerned if it starts itself up, remember Christine?

**truckster** · 10-16-2009, 10:24 AM

Quote:

Originally Posted by UltraBlue71

I'd be a little more concerned if it starts itself up, remember Christine?

Or how about Killdozer?

I guess I'm old.

Back to the original question. Apparently you didn't change anything that might have caused the problem, so that means something either wore out or broke. You've tried the key switch and the alternator, so the only other thing I can think of is the starter solenoid.

Your solenoid has two small posts marked "S" and "R". The starter switch should be connected to the "S" post. The original coil may have been connected to the "R" post. If the HEI is connected to that post, carbon arcing may be causing it to short and provide juice to the HEI even with the ignition switch off.

Kind of a long shot, but it's the only thing I can think of that you haven't tried.

morgan71 · 10-16-2009, 10:34 AM

I had this very same problem on my truck soon after I got it. I first changed the ignition switch as it had one burnt terminal, but no luck. Two days before this happened I had made the one wire altenator swap and had crossed some wires on the voltage regulator, no problems since I corrected those wires.

dan42 · 10-16-2009, 12:47 PM

Truckster, thank you - I'll try that and see if it works. Whatever the problem is , I'll find it, and let you guys know for future reference.

10-10-2009, 08:50 PM	#1
dan42 Registered User Join Date: Feb 2007 Location: Cali Central Coast Posts: 5,191	truck runs when I turn the key off - I just replaced the tumblers 6 months ago, but this afternoon I tried to turn the key of and it kept running. is the switch bad, or is it possible I lost a ground, because I am in the process of taking my bed out? I'm not crazy about having to disconnect the battery to turn the truck off every time. __________________ '67 SWB Fleetside ZZ4/350/Tremec 5-speed/4link/Scott's IFS - and fun as heck! SOLD Click here to support the board Philippians 4: 6-7

10-10-2009, 09:29 PM	#2
dan42 Registered User Join Date: Feb 2007 Location: Cali Central Coast Posts: 5,191	Re: truck runs when I turn the key off - I just took the ground side of the battery off and it kept running. I've never done that before (there was no reason too) but does anyone know if that's normal? __________________ '67 SWB Fleetside ZZ4/350/Tremec 5-speed/4link/Scott's IFS - and fun as heck! SOLD Click here to support the board Philippians 4: 6-7

10-10-2009, 09:38 PM	#3
LockDoc The Older Generation Join Date: Aug 2006 Location: Montezuma, Iowa Posts: 25,651	Re: truck runs when I turn the key off - The switch could be bad or it could be a short. I don't think it has anything to do with the bed. Does it have an HEI distributor? It's probably running off of the Alt. LockDoc __________________ Leon Locksmith, Specializing In Antique Trucks, Automobiles, & Motorcycles (My Dually Pickup Project Thread) http://67-72chevytrucks.com/vboard/s...d.php?t=829820 - Last edited by LockDoc; 10-10-2009 at 09:39 PM.

10-10-2009, 10:13 PM	#4
jay6891 Car Knocker Join Date: May 2001 Location: jefferson,arkansas Posts: 664	Re: truck runs when I turn the key off - I had a 71 burb, and I know this sounds crazy. Would keep running with the key off if the radio was turned off. Turn the radio on and the key off, engine would die. Never did figure that one out. __________________ 68 c-10,91 sportside bed,350 .030 over,4 bolt,10-1 comp,2.05 intake/1.94 exhaust,1.6 Harland Sharp roller rockers,edelbrock rpm cam and intake w/750 carb, 700r4, 3.73 gears,Jacabbs Electronic Igntion w/Accel HEI distributer and super coil. ZR-1 roll pan, filled tailights. Blazer tank. Hidden hitch. 2 1/2" Flowmaster 40's. Parts bought but not installed>> ford 9" posi with disc. CCP front and rear lowering kit 4/5. Cab corners,foor boards,rockers, cab braces, Phatom grill, Painless wiring kit.

10-10-2009, 10:23 PM	#5
Pont406 Registered User Join Date: Aug 2007 Location: West Hills, California Posts: 679	Re: truck runs when I turn the key off - My truck and cars did that also after installing msd boxes. There is a diode you can install in the alt wiring so it stops backfeeding voltage.

10-10-2009, 11:17 PM	#6
dan42 Registered User Join Date: Feb 2007 Location: Cali Central Coast Posts: 5,191	Re: truck runs when I turn the key off - It does have a HEI, but it's been on the truck for over a year with no problems until today. I think I'll start at replacing the switch. __________________ '67 SWB Fleetside ZZ4/350/Tremec 5-speed/4link/Scott's IFS - and fun as heck! SOLD Click here to support the board Philippians 4: 6-7

10-10-2009, 11:38 PM	#7
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Re: truck runs when I turn the key off - do you have an electric fan by chance?

10-11-2009, 02:37 AM	#8
dan42 Registered User Join Date: Feb 2007 Location: Cali Central Coast Posts: 5,191	Re: truck runs when I turn the key off - No electric fan. I tapped the switch a couple of times, thinking maybe something stuck, but nothing. I do have an amp and radio installed but it has worked fine for maybe 3 or 4 months with it until now. __________________ '67 SWB Fleetside ZZ4/350/Tremec 5-speed/4link/Scott's IFS - and fun as heck! SOLD Click here to support the board Philippians 4: 6-7

10-11-2009, 05:27 AM	#9
72freak Rottenwood Garage Member Join Date: May 2005 Location: Marietta, Georgia Posts: 4,321	Re: truck runs when I turn the key off - Unhook the wiring hartness from the key switch and see if its still running. __________________ 2004 Chevrolet Suburban C1500 2001 Chevrolet 2500HD Crew 6.0 1999 Harley Davidson Electra Glide 1972 Chevrolet C-20 Custom Camper "Dump Truck" 1972 Chevrolet C-20 Suburban "Big Green" 1969 Chevrolet C-50 Wedge Hauler "Leonidis" 1966 C-10 2x4 short fleet 327 4 speed "Race Truck" 1952 Plymouth Cranbrook "Rican" (my grandfathers) 1931 Ford Model A Coupe "Black Beauty" 1930 Ford Model A truck "Club Cab" 4x4 Rottenwood Garage and Speed Shop.....where everything must be racy! *It's not just a hobby..It's a LIFESTYLE!!!* Thanks for nothing Barrett-Jackson You cant fix stupid or teach accountability! Time wasters, looky Lous and tire kickers are everywhere!

10-11-2009, 08:00 AM	#11
LockDoc The Older Generation Join Date: Aug 2006 Location: Montezuma, Iowa Posts: 25,651	Re: truck runs when I turn the key off - - After reading through this again I think Pont406 might be on to something. Try unhooking the wiring to the alternator, start it up and see if it will shut off. Make sure the alt. wires aren't touching anything metal. LockDoc __________________ Leon Locksmith, Specializing In Antique Trucks, Automobiles, & Motorcycles (My Dually Pickup Project Thread) http://67-72chevytrucks.com/vboard/s...d.php?t=829820 -

10-11-2009, 08:22 AM	#12
toddtheodd The oddest Todd around Join Date: May 2004 Location: Miami, Florida Posts: 1,418	Re: truck runs when I turn the key off - It's just how great these trucks are. Nothing can kill them. They run no matter what... Even when you try to kill them, they keep running... You can't even turn these bad boys off. __________________ "The greatest pleasure is to vanquish your enemies and chase them before you, to rob them of their wealth and see those dear to them bathed in tears, to ride their horses and clasp to your bosom their wives and daughters." Ghengis Khan IIOY??? Last edited by toddtheodd; 10-11-2009 at 08:22 AM.

10-15-2009, 11:24 PM	#14
dan42 Registered User Join Date: Feb 2007 Location: Cali Central Coast Posts: 5,191	Re: truck runs when I turn the key off - O.K. - I pulled the alternator wire off, and tried to turn off the truck - no dice. I have now replaced the ignition switch with a new one from Brother's, and it still doesn't shut off. Does anyone have any good ideas?? __________________ '67 SWB Fleetside ZZ4/350/Tremec 5-speed/4link/Scott's IFS - and fun as heck! SOLD Click here to support the board Philippians 4: 6-7

10-15-2009, 11:43 PM	#15
LockDoc The Older Generation Join Date: Aug 2006 Location: Montezuma, Iowa Posts: 25,651	Re: truck runs when I turn the key off - - Is there only one wire that plugs into the HEI? Where does the hot wire to the HEI come from? Unplug the hot wire from the Distributor and see if it is hot with the key off. If it is you have it hooked to the wrong source. LockDoc __________________ Leon Locksmith, Specializing In Antique Trucks, Automobiles, & Motorcycles (My Dually Pickup Project Thread) http://67-72chevytrucks.com/vboard/s...d.php?t=829820 -

10-16-2009, 12:05 AM	#16
vectorit What? Join Date: Jun 2007 Location: Southern California Posts: 7,617	Re: truck runs when I turn the key off - I'm real interested to see the culprit to this gremlin. Since years ago, before I began restoring my burb I had the same thing happen to me. Just so happens I was stuck up there in your neck of the woods! Luckily I was up at my Mom's house, and I had a local Napa store near by. The only way I could get mine to stop running was to through a rag on top of the carb to choke out! I had disco'd everything as well, and it would just keep running. There was a bigger problem though. In my case I could not get the truck to go above 3K RPM under load, if I did it would sputter and backfire... Long story short, I ended up going home with a borrowed car. Once there I grabbed a engine I had, and trucked it up there. Had the local Chevron swap out the motors, then drove it home! Took my 327 to the shop for a diagnosis, and apparently all of the rings washed out. Half were broken, and the others were pollished and the edges rounded off. I would have never believed it, but the machinist showed it all to me. He said that I must have over heated or leaned it out? It was a hot day, and I did hot dog it up highway 101 up the steep grades but I know I didn't overheat... One of my all time mystery's I have had in my burbs past. __________________ Chris 1968 K20 Suburban 1972 K10 LWB PU Last edited by vectorit; 10-16-2009 at 12:06 AM.

10-16-2009, 12:43 AM	#18
white 67 Registered User Join Date: Oct 2009 Location: coupeville ,washington Posts: 348	Re: truck runs when I turn the key off - Mine did that when there was a problem with the alternator wiring. I would try another new switch, i had a hard time with my wipers last year becuase i got a bad switch from brothers. I replaced the switch then the motor and then found out my new switch was bad.



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10-16-2009, 09:37 AM	#20
dan42 Registered User Join Date: Feb 2007 Location: Cali Central Coast Posts: 5,191	Re: truck runs when I turn the key off - Internal. 1 wire alternator. It's actually the second switch I got from Brother's - the first I couldn't even get the tumbler installed into. This one had a big chunk of plastic on the bottom of it I had to fish out before I could install it. __________________ '67 SWB Fleetside ZZ4/350/Tremec 5-speed/4link/Scott's IFS - and fun as heck! SOLD Click here to support the board Philippians 4: 6-7

10-16-2009, 10:02 AM	#21
UltraBlue71 Registered User Join Date: Feb 2009 Location: OKC OK Posts: 489	Re: truck runs when I turn the key off - I'd be a little more concerned if it starts itself up, remember Christine? __________________ "You can put lipstick on a pig, sure it's pretty pig, but it's still just a PIG... 71 LWB

10-16-2009, 10:34 AM	#23
morgan71 Registered User Join Date: Oct 2008 Location: Perry OK Posts: 121	Re: truck runs when I turn the key off - I had this very same problem on my truck soon after I got it. I first changed the ignition switch as it had one burnt terminal, but no luck. Two days before this happened I had made the one wire altenator swap and had crossed some wires on the voltage regulator, no problems since I corrected those wires.

10-16-2009, 12:47 PM	#24
dan42 Registered User Join Date: Feb 2007 Location: Cali Central Coast Posts: 5,191	Re: truck runs when I turn the key off - Truckster, thank you - I'll try that and see if it works. Whatever the problem is , I'll find it, and let you guys know for future reference. __________________ '67 SWB Fleetside ZZ4/350/Tremec 5-speed/4link/Scott's IFS - and fun as heck! SOLD Click here to support the board Philippians 4: 6-7

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