Hello all, My first post here and I'm having a bit of trouble. What I have is a 99 Silverado. About every two days I will turn the key and get a no start condition. No starter activity or clicks from the solenoid or anything. It's almost as if the ignition switch has been disabled somehow. Some of the dash gauges will work but some will not. Like for instance, the PNDR lights at the bottom will not illuminate. Key off key on does not fix the issue except on very rare occasions. The most reliable way I have found to correct the issue is to disconnect the battery and rub the terminals together. This for some reason has a reset effect and then, most of the time, the ignition will act normal. Meaning that all the lights come on, all the solenoids click and the truck will start normally. If this does not reset it on the first try, usually a second try will get me going. I have deleted the Vats in the tune(still have the security light on). I have tried jumping the two security wires for the ignition or splicing them together as I have seen on YouTube. I have tried a new neutral safety switch. Yester day I could not get it to reset after three tries so I left it. Tried wiggling the ignition switch aggressively and that did not fix the issue either. My hopes is that someone can tell me where to look.

 

Well I figured it out. Guess I just needed to post about it. As it turns out, it had nothing to do with disconnecting the battery cables. The cable's involvement extended only to the effect they had on the rest of the wiring harness. Specifically the ecm harness. Found that one side wasn't as tight as it could have been after noticing that taking the negative cable off, wiggled the computer harness. Tightened it up and so far so good.

 

FWIW, the problem could’ve just as easily been caused by the battery bolts not staying tight.

I’ve been servicing these trucks for years and the one problem I constantly encounter are the battery bolts not staying tight and/or stripping. Anytime I do an oil change, I’ll check them for movement and usually have to tighten them.

If the problem returns, grip the cable just below the eyelet at the battery and try rocking it side to side - if it moves at all, the bolt is too loose.