Bad Key Cylinder?

[sublimeobs]

Get,or make a remote start switch while it's dead. I just use a quarter some people use a screw driver. Short the solenoid wire to the positive post if the starter cranks,it's not the starter,something isn't sending signal to the starter.If it doesn't crank check for 12 volts to the positive starter lead,check it with a home made test light using an old head light or cigerette light plug in defroster etc. The goal is test it with something that pulls a little amperage not just an led bulb that a firefly could set off. If you have 12v ,change the starter.

^this

The ole Lone Wolf 6000 will quickly show if the starter is at fault. If you're not comfortable shorting across posts or can't easily get to it, get something like this.

 

[Goldilocks77]

I had similar problems that I ended up tracing back to my ignition switch located under the dash on top of the column. What is happening with yours being so inexplicably intermittent and unpredictable sounds hauntingly familiar to my issue. I rigged one of those remote starter buttons in under the dash as a temporary fix until I got time to change the switch out. It kept me from getting stuck a few times.

 

[74Blaze]

I had similar problems that I ended up tracing back to my ignition switch located under the dash on top of the column. What is happening with yours being so inexplicably intermittent and unpredictable sounds hauntingly familiar to my issue. I rigged one of those remote starter buttons in under the dash as a temporary fix until I got time to change the switch out. It kept me from getting stuck a few times.

I had an almost identical experience with my old '79 C10. I realized the Switch at the base of the Column was damaged after I had already installed the Bush-button Starter Switch.

 

[jdoughouston]

For no more than a new key cylinder set costs just replace them. Much cheaper than a starter and should probably be done every so often anyway. When mine went bad you couldn't shut the engine off and the heater wouldn't work. Odd things happen when that stupid thing doesn't work. Seriously, start with the key cylinder. Side note, make sure you have the proper steering wheel tools on hand, otherwise you're going to have a bad time.