I have a 1986 Ford F-250 xl with the 4.9 straight six. A couple weeks ago it sounded like the battery was nearly dead when started so I let off. Turned the ignition again and the starter fired and wouldn’t stop til it tanked the battery despite the key being completely removed. I replaced the starter and solenoid and it seemed to fix the problem. For three days anyway. Up for work and the very same thing again. I went over the wiring and can’t find anything suspicious . Steering wheel ignition ? Short ? Relay ? Any help from someone smarter then me would be appreciated . Thanks in advance

 

Next time, pull the small wire off the solenoid to see if the starter stops cranking. After everything you had replaced, I would expect it to stop cranking. Then start looking for a problem with the ignition switch or wiring issues between the ignition switch and solenoid.Hopefully, your starter has been trashed by now.
If you change the ignition switch (they are cheap), mark its postion as its position may be adjustable, so you get it back in its original position.

 

You spent a load of $$$ so far and why not go for a few dollars more to SEE just what is happening.
Purchase a decent test light.

Connect the ground clip of the test light to the WIRE that raski suggested you remove.
Stick the test light on to a good piece of sheet metal .
Now when you turn the key to the start position , that test light will lite.
When you release the key IT SHOULD GO OUT ,Does it ?
If it does , try it several times to make sure it works all the time
If it goes out , there is a starter problem, if it doesn't there is a problem with the switch mounted on the lower part of the steering column.
The problem could be the switch or the linkage within the steering column.. It will be easy to pin down because you can SEE by just looking at the test light.
When you have determined the cause and repaired it , just reinstall the wire back on the solenoid.

 

Thanks guys for your responses. I apologize for my ignorance as I have just recently started to try and do my own repairs due to not being able to find an even remotely honest decent mechanic anymore so my experience is limited to say the least. I know many p things may be elementary to you but it’s all new to me. I greatly appreciate the advice and help.

 

Could improper shimming off the new starter I put in cause this in any way shape or form ?

 

That will not cause the starter to continue on cranking after the key is released.

. Improper shimming will damage flywheel teeth and the Bendix gear on the starter due to the two not meshing together squarely.

 

There is a difference between a starter for a manual trans engine as compared to an automatic trans engine. It's a little late now , but ALWAYS compare the replacement starter to the one removed, especially the nose end of the starters..
If the selling agency or the buyer doesn't specify for a vehicle with an auto trans you could get the wrong starter assy.

 

For the life of me I cannot find the switch you mentioned under the steering column. The only thing under there are the various wiring harnesses

 

Just type in 1986 Ford ignition switch image and location.

That should help so you have some idea what it looks like..

 

It does not look like your typical switch. Hopefully, this will help you identify it.Notice that its mounting holes are slotted. Mark the original's position before removing the screws.

https://www.rockauto.com/en/moreinfo...t=4700&jsn=490