I just went out to move the wife's truck and the key-switch refuses to turn to the CRANK/START position.

I tried several different keys that have always worked before.

Luckily, it happened at home.

The switch will turn to all positions except START.

I was able to start and run the engine by jumping the starter solenoid wires.

I am going to install a push-button start so she can use the truck.


Can someone point me in the direction of a TECH article that explains how to replace the switch ??


It is LE cab 1991.5 with tilt-column.


I am thinking that all functions are contained within the key-switch itself, or does the key operate a rod that works a separate switch down on the column ??

Thanks.

 

They all use the same switch mounted on the column and operated by a rod. There is also a neutral safety switch and a starter relay.

 

The problem is definitely either the key-switch or the rod-operated mechanism.

It is hard to see up under there; where exactly is this rod-operated mechanism ??

The key will turn to RUN but will turn no further to the START position.


I got her up and running by installing a dash-mounted starter-button.

As it is now, we turn the key to RUN, then push the starter-button to crank the engine.

I actually like it this way better, but I am afraid that silly key-switch may decide to also quit turning even to RUN.

 

I've taken alot of these apart.

There are a few T20 screws that hold the steering column plastics together, they go up through the bottom. when you get the plastic off you'll see the KEY CYLINDER w/key actually goes into the SWITCH itself which is where the wires and stuff come out and go to their functions etc., The black plastic that the key cylinder is in has a series of gears in side it, so when you turn the key you're turning a gear that turns another gear which turns another gear that has a peg on it that actually goes into the column and locks into a slot, this is what unlocks the column and actually lets the truck start!!

Often times i've seen many where a ball or a tooth comes off inside the switch and gets lodged in the switch and stops it from going all the way to the start position, like i said it's actually mechanical the piece inside the steering column has to be turned for it to start but the electronics to the swtich have to hooked up as well.

sounds complicated but it's easy to do, you will need security T20 trough with the hold in the middle so you can remove the ign. switch itself.

It looks like this, when you get it off, pop the white plastic backing off and inspect. fix what's broke, and glue the plastic back down so none of the internals pop out since they are under pressure. should be very easy for you...

It looks like this , that hold is where the key cylinder goes ----the shaft you see with the flat on the end is what locks into the column and turns the metal in the column so it'll start and unlock the wheel/shifter etc

 

I knew that sooner or later you would amount to something.


Thanks ever so much for this helpful post and pictures.

I believe this needs to be in the "stickies"; I looked there first and didn't find anything.

 

It's got my vote, put'er in,& thanks well done.

 

Nice job brandon

 

Hey BK, I've seen that type of problem before, on the "new" style of column that uses the type of ignition switch shown in Brandon's pictures. What I have seen fail isn't the switch, but just the lock cylinder. On the end of the lock cylinder is a semi-circular piece of metal that engages with the switch and turns it. I have seen several times where a chunk will break out of that piece and prevent you from turning the switch all the way.

As you feared, it will eventually get worse as more metal crumbles away. If you remove the lock cylinder from the switch, you should be able to easily see if that is the problem, and if so, you just need a lock cylinder and not the switch.

 

I found this in the stickies; it was not categorized where I would have thought it should be, which is why I didn't find it at first.

https://www.dieseltruckresource.com/...r-t241339.html



My problem was as torquefan suggested.

And yes, it did get worse.

I knew we were probably on borrowed time until the key-switch quit for good.

Luckily, AGAIN, at home, in the driveway, she had just got back from several errands and parked the truck.

I went out to relocate it and the key refused to turn at all.


I tore into the column and removed the switch assembly.

When I pulled the key-cylinder, I found that little metal collar was missing a chunk and that chunk had migrated to where it had locked things up.


As I had already installed a push-button START, I decided to see if I could re-engineer that broken collar and get it back in action.


I used a file to square up where the chunk had broken out.

I cleaned and lubed the whole mess and re-assembled.


The key now turns in the cylinder easier than it has since we first bought the truck, some five or six years ago.

No more push in wiggle-jiggle hold your mouth just so to get it to turn; smooth as silk.


Although the doors still use the same key, it was obvious from all the Gorilla-Glue and black-tape around the plastic bulb ring that I was not the first to be in there messing around.


I saw no evidence of any melted terminals or hot wiring.


Maybe this poor-boy repair will last a while.


Thanks everyone.