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Mechanical question about ignition switch

5K views 21 replies 6 participants last post by  roger1 
#1 ·
This question is regarding the stock ignition switch in my '83 El Camino with an automatic transmission and tilt column.

The ignition switch is working but the engine will turn over when the shift lever is in any position. It's only supposed to start when the shift lever is in Park or Neutral and none of the drive positions. I looked in the factory service manual and it says there is a mechanical stop in the key switch mechanism that prevents it from starting when the shift lever is in any drive position. That's obviously my problem but the manual doesn't tell me where this stop is.

My question here is what I have to replace to fix this. I believe this column mounted ignition cylinder is pretty much the same from the early 70's all the way to around 1990 in most GM cars. So, I'm hoping someone here has experience with this.

I'm wondering if I replace the rack and pinion with one of these kits if it will fix my problem:



Any help will be appreciated.
 
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#2 ·
I've never noticed a mechanical stop...but there is a neutral safety switch on top of the column under the dash that prevents the starter from being engaged when column shift lever/collar is in any position other than Neutral or Park.

I'd be looking at that sliding switch.
 
#3 ·
I've never noticed a mechanical stop...but there is a neutral safety switch on top of the column under the dash that prevents the starter from being engaged when column shift lever/collar is in any position other than Neutral or Park.
I'd be looking at that sliding switch.
No, the p/n electrical switch on these connects only to the ECM.

The purple wire to the starter solenoid is connected directly to the ignition switch so it has to be a mechanical stop within the column.

I have the '83 factory service manual. Here's what it states:

"Mechanical Block on the Automatic Transmission Shift Lever Prevents Starting Except in "N" or "P"."

I just can't find where the part is from the diagrams. Also, I wonder if I do find the broken part whether it will be available or not.
 
#5 ·
I think this mechanical lock-out might be cast into the shifter housing.

I believe my 79 C-10 is the same (with tilt), but it has been almost 30 years sicne I tossed the auto for a manual.

But I seem to recall that when my now empty shifer housing vibrates down,
the key will not turn to start. (take this with a grain of salt---I actually parked the truck nearly 10 years ago and it has not moved since)
 
#7 ·
I think this mechanical lock-out might be cast into the shifter housing. I believe my 79 C-10 is the same (with tilt), but it has been almost 30 years sicne I tossed the auto for a manual.
But I seem to recall that when my now empty shifer housing vibrates down,
the key will not turn to start. (take this with a grain of salt---I actually parked the truck nearly 10 years ago and it has not moved since)
You may very well be correct. It's in there somewhere for sure.

I've studied the exploded diagram of the column in the service manual and I cannot determine from that where it is though. One thing for sure though is that it is not in the rack that I posted a photo of. If that were broken, it wouldn't be working at all.
 
#6 ·
I've had the tilt column in my '75 GMC apart to replace the rack in the picture. The little black piece is on the end of the ignition switch mechanism and as it rotates it moves the large pot metal rack piece. The rack pulls a small rod up and down, and this rod runs down the column to the electrical part of the ignition switch. If the rack breaks (a common problem) it will not pull the rod properly and the electrical switch will not work.

The rack is a cheap part, but requires quite bit of assembly to get to it. You have to pull the steering wheel and most of the parts inside the tilt column to get to the rack on the end of the switch mechanism. There are several online articles that explain how to pull the column apart. From what I remember, it took me about 3 hours to replace the rack in my column. I also tightened up the bolts that hold the tilt section on the column, so I got two fixes in one job.

Bruce
 
#8 ·
Its a mechanical lockout.
The picture shows the "bowl" and shroud assembly. It has notches inside .The ignition switch actuator rod has the rod and also the cast piece that goes into the rack actuator.
The switch actuator rod has notches cut into it, that coincide with the notches in the "bowl assembly (inside) that block the key from turning the switch to start when in park or neutral.
When you get it apart far enough ,you will see what I mean. I have had a bunch of these columns apart in the past.
 

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#9 ·
Thanks! I thought there would bound to be someone here that knows.

So, what part most likely do I have broken? And is this going to be available or would it mean going the wrecking yard route?

I can wire a relay to break the connection on the purple wire controlled by the electrical P/N switch that is hooked to the ECM. Maybe it's not worth my trouble to fix it. If the part I need is not available, I think I should go that route.
 
#10 ·
It may have been apart before, and some one put the wrong rack actuator piece in it. Just need to take it apart and look to See what is missing.
Maybe someone was in there grinding on some parts.
Before you take the "bowl" off , look at the mechanism so it makes sense to you. Its hard to explain. As soon as you see it, you will get it.
 
#13 ·
I wouldn't be surprised if it were excessive force. I'm the second owner but the guy I bought it from wasn't a car guy at all.

Do you mean the rack? That's the cast piece right? I would figure that would break rather than bend.
 
#14 ·
The rack will get a crack in it
With repeated use that crack gets bigger and bigger.

It will usually crack at the top or the bottom.

So--the section that did not crack bends---and in the case of tilt, will not pull the rod far enough to start the car.

Not sure, but I thought non-tilt columns push the rod to start.
I think the non tilt and the tilt columns also use different switches
 
#15 ·
I guess the way to explain it would be...
A semi truck and trailer is at a certain height. Use that for the actuator rod/assembly. The actuator has a hump in it . We will call the hump the truck.
The bowl has several bridges at different heights. They are in a row around the inside circumference of the bowl. The "bowl" turns when moved from park to drive etc.
each gear has its own overpass at different heights. The park and neutral overpasses are high enough to let the truck go under (the hump in the rod), the reverse and drive gears have overpasses that are to low for the truck to go under.The low overpasses or bridges are where the lockout is made. The park neutral bridges are high enough to let the truck go under and then the switch can be turned all the way to start,instead of getting blocked in the run position by a bridge.
Its late...god I hope you can make sense out of this.:thumbup:
 
#16 ·
#17 · (Edited)
I found a fantastic write-up on these columns:

http://www.crankshaftcoalition.com/wiki/images/d/d6/Jazzman_Steering_Rack_Rebuild.pdf

Look on page 69 as it is clear how the lock-out works in the diagram on that page.
On mine, either the cast piece on end of the rod or that slotted ledge inside the bowl is. I won't know which until I tear it down. Either way, a PO must have forced it to make one of those 2 things break.
 
#19 ·
I have an old tilt out of a Dodge pickup
it has the mechanical lockout as well
The tilt part is a bit wobbly----that's why I changed it.

Interesting thing----pretty much the same column as the GM
Both are Saginaw columns
And the Dodge even uses a GM ignition switch---probably turn switch too---except for the connector.
The rod is positioned a bit different as the switch is mounted on the side of the column vs the top on GM.

But the shift collar might be the same
No shift lever in mine---I added tilt to a manual trans Dodge 150----something dodge did not offer in the 80s on MT trucks
 
#20 ·
Update

I'm back from out of town and got time today to disassemble my column. The part broken was the one I figured had to be.





If anyone here is parting out one of these columns from a G Body and would sell me this ignition rod, I'd sure be interested.

Thanks to all for the help on this.
 
#21 ·
What do 'ya think guys?
I think it will be as strong or stronger than new.

I blasted the area to clean and rough up, epoxied it with JB Weld and sanded it smooth. I filled the channel with epoxy for extra strength.





 
#22 ·
Btw, in this photo you can see exactly how it exactly works.
The wedge shape on the rear of the cast piece attached to the end of the rod is blocked unless lined up at the arrows I put on the photo (when bowl rotates with the shifter).

 
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