Hey Guys, I need your help. Firstly, I've searched the forum and I can't find an answer to my conundrum. Maybe I'm a ratard when it comes to key words or searching, so feel free to direct me to a thread that might help if you prefer not to type everything you know out. I also have to disclaim I'm helping a friend with his Chevy, not mine. He has a 1992 Silverado Z71 1500. It's a V8 and, I think, its still carburated. The initial problem was that it wouldn't start consistently and often it was when it got warm that the problem started. This has been a recent issue as about 10 days ago. Also the Oil Pressure gauge jumps all over sporadically with no consistency. Sometimes it will level off in the middle and be normal, other times it'll bounce around. Truck will start and run or idle forever practically, but it's a hit and miss if you turn it off and try to restart it. Might as well gamble on the odds because it's 50/50.

Troubleshooting: It was initially assumed that the Starter was bad, but the truck doesn't even try to turn the crank. Nothing to the starter, so we were a bit skeptical that the Starter was the issue. Regardless we took it out and took it down to be tested. It tested better than the New one they had on hand. Took it back and put it back in. Truck fired up. Took it down to the parts shop to diagnose with the hand held Comp and it would register, say it was reading, but spit out no info or reading. Second theory, it was the Starter switch. Bought a new BSM starter and replaced the switch. Now the truck won't start and the column won't move out of the Park position. Double checked the Starter Switch hook up and it is correctly reinstalled. No idea why it won't move out of "P" when the ignition is in the ON position, no idea why the truck still won't start. Sounds like a wiring issue to me, but I have no idea where to start and my friend isn't mechanically savvy, although I'm no mechanic either, just more familiar. Other things we've verified: Battery tests fine, Alternator was replaced 6months ago, Fuel Pump is New, Fuel Filter is New. No check on Cap, Rotor, or Plugs, but there is nothing happening from turning the key to engage anything - both before and after replacing the Switch - so the assumption is the issue lies with the Ignition Start point. Nothing happens regarding starting or the crank attempting to turn. Lights and interior accessories all work. Dash lights up, just no click and turn over. Any ideas out there? What the F is going on? Did we mess something up with the column shifter when we replaced the Starter Switch? Any clue why the truck would start sometimes, but not other times without even attempting to crank? Thanks for ALL of your feedback!

 

Have you looked into your park/neutral switch on the side of the trans?

 

I have not. Are you suspecting this would potentially alleviate the starting issue, that it won't disengage from Park, or possibly both? I'll try replacing that. Is there a way to test it first?

 

The way it works is power is sent from the ignition switch, through the park/neutral switch ( so that you can't start it in drive), then goes to the "S" terminal on the starter.

When the truck is having its no start condition, grab a test light, ground the clamp and touch the end to the purple wire on the starter - that's the smaller one with a small eyelet. If it lights when your helper turns the key to crank, then the problem lies elsewhere. If the light does not illuminate, then move back to the transmission, unplug the park/neutral switch (See below) and touch the end to the terminal that has a yellow wire behind it. Again, have your helper turn the key to crank. If it lights, plug the connector back in, and back probe (see below) the purple wire on the same connector. If it does NOT, suspect a bad park/neutral switch, or the transmission is not fully in the park position.


Slide the pin inside the insulation till it touches the metal terminal just inside the connector - never puncture wire insulation this way!


Should be more or less where your switch is

 

Hey IMINRU,

I’m sorry to hear that you are experiencing these concerns with your truck. I cannot guarantee anything, but I will be glad to look further into these concerns for you. Please send us a private message or an email to socialmedia@gm.com if we can be of any assistance. Thank you.

Kristen A.
GM Customer Care

 

So, after being away for a bit I've finally been able to apply the feedback above and see what the results were. I've replaced the Neutral Safety Switch, which I located at the base of the steering column, and that didn't solve the problem. I also replaced the 30A Ignition fuse and Battery fuse. Still no luck. I'm baffled. It'll just have to go into the shop.