No Crank Diagnosis... Thinking Nss But Not Certain

[gogmorgo]

So after spending 10 minutes in cuffs and a few minutes in the back of a cruiser until the cop dug the registration out of the glove box and my license out of my wallet before he believed that I wasn't stealing my own truck, I've decided it's time to really figure out what's wrong with it.

'91 4L auto.

 

For the last couple months, I've been having an intermittent no-crank issue. I was thinking neutral safety switch, because the first few times it wouldn't crank when I turned the key, I could "solve" the issue by shifting into neutral, but no luck with that in the last few weeks. I've also intermittently had no reverse lights.

But now I'm also beginning to suspect the ignition switch, because this morning everything died when I turned to "start", but came on again when I went back to "on". Don't remember that happening before. In the past, it was usually as if the key was still at "on" when I tried to start it.

 

So far, crawling underneath with a fat screwdriver across the solenoid has worked to start it (with the key on, it fires right up) but I'm getting the impression that it's not always a good idea to let other people see me doing this, and lately it seems to do it when I've parked in the dirtiest or wettest spot possible, and with break-up approaching, I'm expecting a lot more of that...

 

Today's, er, incident may be the motivation I needed to clean up the nss as per http://jeepin.com/features/nss but is there something else I should be looking at? What should I do to find the root issue(s). It'll be a while before I can get my truck into a warm and dry shop to look into it (the tractor lab I usually "borrow" after the janitors have left is currently full of tractor) but the last time I went looking for the nss I wasn't sure I'd found it.

[Biotex]

Look into the ingnition switch on top of the steering column up under the dash. When you turn the key, it slides a rod forwards which moves a set of contacts inside the ignition switch. That switch is held on with 2 bolts, and is adjustable. I've seen where the switch is either just bad, or out of adjustment. They are not very expensive, but not a lot of fun to replace.