Odd electrical problem, '72 blazer ignition switch woes - The 1947 - Present Chevrolet & GMC Truck Message Board Network

masterbeavis · 07-31-2005, 10:46 PM

The key stopped turning off the ignition a while back, so I wired up a switch to shut the truck off. Yesterday, the key would not turn any of the accessories off, so today I went and purchased a new ignition switch. I replaced the switch, and still had the same problems. Ignition would not turn off, and accessories still would not shut off. After cycling the key a couple of times, the ignition began to "try" to turn off, and soon it began to shut off accesories as well, but not every time like its supposed to. Is there some vauge anchient indian secret to apeasing the gods here?

Thanks in advance.

jhow66 · 07-31-2005, 11:59 PM

Sounds like your key tumbler is the problem. You can buy them new also.

masterbeavis · 08-01-2005, 12:33 AM

Quote:

Originally Posted by jhow66

Sounds like your key tumbler is the problem. You can buy them new also.

Key tumbler? the actual housing for they key? I dun get it (yet)

jhow66 · 08-01-2005, 12:41 AM

Quote:

Originally Posted by masterbeavis

Key tumbler? the actual housing for they key? I dun get it (yet)

Yes--the cylinder that the key goes in. What you bought was what the wires plugged into--right? When you buy a new cylinder you will get a new key also (old one would not fit).

jtminton · 08-01-2005, 11:36 AM

My truck did that, and it turned out to be the stater solenoid sticking. Just a thought.

masterbeavis · 08-01-2005, 10:00 PM

Quote:

Originally Posted by jtminton

My truck did that, and it turned out to be the stater solenoid sticking. Just a thought.

If it is sticking, wouldnt it be killing power, instead of leaving it on?

And I dont see how I would need a new cylinder, all it does is act like a fancy screwdriver with tumblers.

**pjmoreland** · 08-02-2005, 01:33 AM

Get your truck into the state where the key is in the "off" position, and the engine is still running, and then unplug the wiring harness from the back of the ignition switch. If the engine continues running, then maybe the problem is not in the ignition switch at all and it's somewhere else.

By any chance are you turning your key all the way to the left when turning the engine off? The "ACC" position is all the way to the left, and off is with the key straight up and down. The only reason I mention this is because several months ago there was a board member with a similar problem, and it turned out he was leaving his ignition in the "ACC" position.

masterbeavis · 08-02-2005, 02:20 AM

Quote:

Originally Posted by pjmoreland

Get your truck into the state where the key is in the "off" position, and the engine is still running, and then unplug the wiring harness from the back of the ignition switch. If the engine continues running, then maybe the problem is not in the ignition switch at all and it's somewhere else.

By any chance are you turning your key all the way to the left when turning the engine off? The "ACC" position is all the way to the left, and off is with the key straight up and down. The only reason I mention this is because several months ago there was a board member with a similar problem, and it turned out he was leaving his ignition in the "ACC" position.

With the old switch, the motor stayed on regardless of the position of the key. ACC, off, run, key out, it didint matter. Now the motor "thinks" about shutting off more when not in the run position.

jtminton · 08-02-2005, 09:32 AM

Quote:

Originally Posted by masterbeavis

If it is sticking, wouldnt it be killing power, instead of leaving it on?

And I dont see how I would need a new cylinder, all it does is act like a fancy screwdriver with tumblers.

From what I understand, when the solenoid is engaged, it bypasses the ignition and sends 12v to the coil to start the engine. If the solenoid sticks, then the key is not going to do anything. Try dropping the starter and taking off the solenoid. Then grease the piston really good and put it all back together and see if it works.

**pjmoreland** · 08-02-2005, 01:33 PM

I think jtminton is onto something. You could try disconnecting the yellow wire from the outer terminal of your starter and see if the problem goes away.

masterbeavis · 08-03-2005, 12:14 AM

I will have to give that a try.... Damn parts house starters....

jhow66 · 08-03-2005, 01:26 AM

If your solenoid sticks your starter would stay engaged.

bouncytruck · 08-03-2005, 11:45 AM

What kind of condition is the plug that goes into the back of your ignition switch? I've had two go bad (one on each blazer)

masterbeavis · 08-03-2005, 10:01 PM

Quote:

Originally Posted by bouncytruck

What kind of condition is the plug that goes into the back of your ignition switch? I've had two go bad (one on each blazer)

Looks to be in excellent condition to me. No short insulation, discolored wires, contacts looked good....

masterbeavis · 08-04-2005, 01:38 AM

well, it looks like JTminton was right. had key off, truck still running, started whacking the solenoid, truck shut off. It was like magic. Thanks for the input guys :beer:

jtminton · 08-04-2005, 09:36 AM

Quote:

Originally Posted by masterbeavis

well, it looks like JTminton was right.

Now if only Mrs. jtminton could get that through her head sometimes. . . . .

masterbeavis · 08-04-2005, 04:31 PM

Quote:

Originally Posted by jtminton

Now if only Mrs. jtminton could get that through her head sometimes. . . . .

Well, I would imagine that in her eyes, its only sometimes you are partially right? But even then you are wrong, cuz she has the right to change the criteria.....

07-31-2005, 10:46 PM	#1
masterbeavis Having issues Join Date: Jul 2005 Location: Eldorado Ca, an hour east of sacramento Posts: 696	Odd electrical problem, '72 blazer ignition switch woes The key stopped turning off the ignition a while back, so I wired up a switch to shut the truck off. Yesterday, the key would not turn any of the accessories off, so today I went and purchased a new ignition switch. I replaced the switch, and still had the same problems. Ignition would not turn off, and accessories still would not shut off. After cycling the key a couple of times, the ignition began to "try" to turn off, and soon it began to shut off accesories as well, but not every time like its supposed to. Is there some vauge anchient indian secret to apeasing the gods here? Thanks in advance. __________________ Quando Omni Flunkus Moritati. The Man's Prayer: "I'm a man, but I can change, if I have to, I guess."

07-31-2005, 11:59 PM	#2
jhow66 Registered User Join Date: Jun 2002 Location: Knoxville Tenn. Posts: 3,058	Sounds like your key tumbler is the problem. You can buy them new also. __________________ 56 Chevy Bel-Air 2dr. HT (purchased new) 71 Chevy Cheyenne SWB PU (502HO) 65 GMC short bed step--work in progress and my gofer

08-01-2005, 11:36 AM	#5
jtminton II Timothy 4:2 Join Date: Mar 2005 Location: Fort Worth Posts: 361	My truck did that, and it turned out to be the stater solenoid sticking. Just a thought. __________________ 72 C-20 2WD LWB Custom Camper Deluxe 350 4 Speed "Project Lazarus" MY TRUE PRIDE AND JOY "Dangit, Bobby, people will see that oil stain and think I'm a drunk."

08-03-2005, 12:14 AM	#11
masterbeavis Having issues Join Date: Jul 2005 Location: Eldorado Ca, an hour east of sacramento Posts: 696	I will have to give that a try.... Damn parts house starters.... __________________ Quando Omni Flunkus Moritati. The Man's Prayer: "I'm a man, but I can change, if I have to, I guess."

08-03-2005, 01:26 AM	#12
jhow66 Registered User Join Date: Jun 2002 Location: Knoxville Tenn. Posts: 3,058	If your solenoid sticks your starter would stay engaged. __________________ 56 Chevy Bel-Air 2dr. HT (purchased new) 71 Chevy Cheyenne SWB PU (502HO) 65 GMC short bed step--work in progress and my gofer

08-02-2005, 01:33 AM	#7
pjmoreland Senior Member Join Date: Jan 2005 Location: CA Posts: 6,043	Get your truck into the state where the key is in the "off" position, and the engine is still running, and then unplug the wiring harness from the back of the ignition switch. If the engine continues running, then maybe the problem is not in the ignition switch at all and it's somewhere else. By any chance are you turning your key all the way to the left when turning the engine off? The "ACC" position is all the way to the left, and off is with the key straight up and down. The only reason I mention this is because several months ago there was a board member with a similar problem, and it turned out he was leaving his ignition in the "ACC" position.

08-02-2005, 01:33 PM	#10
pjmoreland Senior Member Join Date: Jan 2005 Location: CA Posts: 6,043	I think jtminton is onto something. You could try disconnecting the yellow wire from the outer terminal of your starter and see if the problem goes away.

08-03-2005, 11:45 AM	#13
bouncytruck SKINNY TIRES RULE! Join Date: Sep 2001 Location: Bothell, WA Posts: 11,038	What kind of condition is the plug that goes into the back of your ignition switch? I've had two go bad (one on each blazer) __________________ bouncytruck 1972 K5 The Hauler 1994 K1500 Suburban The Daily2010 Kia Soul Wife's Ride2014 Fiat 500L

08-04-2005, 01:38 AM	#15
masterbeavis Having issues Join Date: Jul 2005 Location: Eldorado Ca, an hour east of sacramento Posts: 696	well, it looks like JTminton was right. had key off, truck still running, started whacking the solenoid, truck shut off. It was like magic. Thanks for the input guys :beer: __________________ Quando Omni Flunkus Moritati. The Man's Prayer: "I'm a man, but I can change, if I have to, I guess."

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