Im thinkin ignition switch problem

[Angrywood]

In my 62, the previous owner installed a push button start which is to the right of the attached picture.

Recently, the truck while driving just shuts off as if someone turned the key off. Once it shuts off, the dash indicator lights come on as if i was just going to start it up, and turned the key to the run position. I pulled the ignition switch and push button off just to check to make sure everything had a good connection. It appears so. After it shut off today, i realized if i turn the key all the way over to the “start” position, and push the push start button if fires up. If i dont turn the key all the way over it just cranks as if the ignition was off.

Any ideas on a fix for this? Not sure if its fixable because its too worn out and dont want to necessarily buy a new switch and have to rekey the door locks etc. I have no problems getting rid of the push button start either. Not sure why that was put in unless there was something wrong with the ignition switch anyways.

Thoughts are appreciated

[franken]

The hole above and to the right of the key releases the part the key goes in and allows the ring with the three slots to unscrew to remove the switch. Or that's how 67-72 ones are anyway...
I'd look at the wiring and see how the pushbutton is wired, jump around it and see if the key only works to start. If not it looks like a new switch is needed.

[Rolland]

An old switch can become a real loose cannon. On another forum a man reported that his GMC started up by itself and drove into his porch.

[Angrywood]

Originally Posted by Rolland

An old switch can become a real loose cannon. On another forum a man reported that his GMC started up by itself and drove into his porch.

Was thinking the same thing that it just got loose. But when i checked the wires it seemed good. Dont know how one started and drove up on a porch though…

[Steeveedee]

Not with these trucks. But I recall a guy who had an Astrovan that would lock its own doors and then unlock them again...repeatedly. He was the Scoutmaster for our troop, and we'd be loading and unloading gear in the parking lot, and you could hear the locks cycling on...off...on...off, with nobody even close to the van. Maybe he had a remote in his pocket? Idunno.

[Angrywood]

Originally Posted by franken

The hole above and to the right of the key releases the part the key goes in and allows the ring with the three slots to unscrew to remove the switch. Or that's how 67-72 ones are anyway...
I'd look at the wiring and see how the pushbutton is wired, jump around it and see if the key only works to start. If not it looks like a new switch is needed.

Sounds like a good idea. Didn’t think of doing that. Thank you

[Angrywood]

Looking at the spaghetti bowl of wires…. This is what ive found and poses another question. On the ignition switch itself… all prongs had wires attached except for the ACC spot. On the push button it had the hot wire that was spliced into the hot wire on the switch and then another wire. Would that other wire on the push button go to the ACC spot on the switch?

Thanks in advance

[MT65]

What color are the wires your telling us about…accessories is usually brown..purple goes from switch to starter ….red is power to the switch

[Angrywood]

Originally Posted by MT65

What color are the wires your telling us about…accessories is usually brown..purple goes from switch to starter ….red is power to the switch

That’s a good question…. So i took a look at it….wires are old and discolored. So it might be hard to say. Red is battery terminal. The ground im guessing is the tan looking color that is suppose to be white? The purple or possibly brown is to the solenoid. And the ignition is the pinkish. The wires that connect to the push button is red…. And i did not look to see if that was spliced into another wire somewhere. Ill attach a picture. Ordered a new switch so ill find out sooner than later if its a switch issue or wiring

[MT65]

Yes, the ignition would be pink, if I don’t forget, I’ll grab a schematic today and verify your tan wire. Judging from the visible butt splicing and poor crimps on terminals, you may have a combination of problems.
The purple wire should only be hot when the switch is in the start position…with the push button hooked to the red, presumably from the starter switch…guess I would have to trace out some of it…it appears to be hooked to a smaller gauge red on one side…..this situation you’re in is the reason I rewire anything I own if the wiring is in that condition….takes all the guesswork away. These trucks were not wired very well new, yours has seen better days

[MT65]

Originally Posted by MT65

Yes, the ignition would be pink, if I don’t forget, I’ll grab a schematic today and verify your tan wire. Judging from the visible butt splicing and poor crimps on terminals, you may have a combination of problems.
The purple wire should only be hot when the switch is in the start position…with the push button hooked to the red, presumably from the starter switch…guess I would have to trace out some of it…it appears to be hooked to a smaller gauge red on one side…..this situation you’re in is the reason I rewire anything I own if the wiring is in that condition….takes all the guesswork away. These trucks were not wired very well new, yours has seen better days

I found no tan wire on the schematic, used American Auto Wire direct fit harness schematic…..red is power in..brown is accessories…purple is starter solenoid…pink is ignition

[Angrywood]

Originally Posted by MT65

Yes, the ignition would be pink, if I don’t forget, I’ll grab a schematic today and verify your tan wire. Judging from the visible butt splicing and poor crimps on terminals, you may have a combination of problems.
The purple wire should only be hot when the switch is in the start position…with the push button hooked to the red, presumably from the starter switch…guess I would have to trace out some of it…it appears to be hooked to a smaller gauge red on one side…..this situation you’re in is the reason I rewire anything I own if the wiring is in that condition….takes all the guesswork away. These trucks were not wired very well new, yours has seen better days

The splicing is where he ran the hot to the push button. The crimps on the terminal is a temporary as I’m troubleshooting through this. ��

Thank you for the schematic. That should help.

I also learned that the cause of the original problem with the engine just turning off could be the coil. Its getting to hot then failing. After it cools down it starts right up again. Is there a fix for that or is it just better to buy a new one. This one is only a couple years old and hasn’t been actually used much.

[franken]

I'm not sure I'd just assume the coil is the culprit by guessing. More testing is needed.
That said no doubt one of the parters on here probably has a pile of coils, or a pick a part nearby has one used for cheap. Maybe not so much in southern CA...