Ignition engages whenever it wants to?????

Drove about 10 miles today ,the truck was warmed up,when I put it in park the starter engages all by itself while the engine was still running.
On the way home it did it while I was in drive about 35 mph I threw it in neutral and shut it off and coasted to a stop...it started right back up with no issues the rest of the way home.
I noticed that while driving I see my drive selector flashing overdrive...sometimes it shuts off like its between gears...sometimes it stay on like it supposed to.
Is this a faulty Ignition switch?
Any help is greatly appreciated!!!!!!!
99
4.3
4wd
LT

CS

Drove about 10 miles today ,the truck was warmed up,when I put it in park the starter engages all by itself while the engine was still running.
On the way home it did it while I was in drive about 35 mph I threw it in neutral and shut it off and coasted to a stop...it started right back up with no issues the rest of the way home.
I noticed that while driving I see my drive selector flashing overdrive...sometimes it shuts off like its between gears...sometimes it stay on like it supposed to.
Is this a faulty Ignition switch?
Any help is greatly appreciated!!!!!!!
99
4.3
4wd
LT
CS


Hard to say with out proper testing.
Start it up and pull crank fuse.
That will eliminate the ign switch from turning it on.
If it till does it with crank fuse pulled it is father down the line.
Starter relay or starter solenoid or shorted wire.
Check the wiring on and at the starter solenoid.
When it does it I would pull starter relay first and see if the starter quits running.
Also the neutral safety switch should keep the ign switch from turning on starter in drive position.
Next time put it in drive and see if that breaks the circuit to starter.
Post back how it goes.
MT

I cant start the truck while its in drive gear.
You said a "crank fuse"? Do you know what # that is?
Does it say crank fuse?
The starter relay you mentioned,is that also in the fuse box?
Thanks for your help

I cant start the truck while its in drive gear.
You said a "crank fuse"? Do you know what # that is?
Does it say crank fuse?
The starter relay you mentioned,is that also in the fuse box?
Thanks for your help

You will find both in the under hood fuse and relay box.
There should be a be picture on the under side of the fuse /relay box cover.
MT

Did you buy it used?? Is possible that a previous owner installed a remote starter system that is either wired wrong or is now malfunctioning.

Hard to say with out proper testing.
Start it up and pull crank fuse.
That will eliminate the ign switch from turning it on.
If it till does it with crank fuse pulled it is father down the line.
Starter relay or starter solenoid or shorted wire.
Check the wiring on and at the starter solenoid.
When it does it I would pull starter relay first and see if the starter quits running.
Also the neutral safety switch should keep the ign switch from turning on starter in drive position.
Next time put it in drive and see if that breaks the circuit to starter.
Post back how it goes.
MT
I am new to this forum, happened onto your post through a search, I just bought a 2001 S10 regular cab short box with a automatic and 2.2 engine. I started fine and ran great, until after I got home (around 30 minutes later) and shut it off then restarted it, the starter at different times kept trying to reengage while running in park. But hasn't done it since, but I haven't taken it anywhere, due to the problem, maybe it would only do it after driving for 30 minutes and getting warm?? It's not on the road yet, borrowed a dealer plate to drive home. Any thoughts would be greatly appreciated.

When it is doing it as said in upper post pull crank fuse and see if that stops it.
Welcome to AF.
For more help best to find and hit New thread button and start a new thread/post.
Let us know how it goes.