2005 silverado 1500 sometimes won't start

[cybern8]

i have a sporadic and very annoying problem with by 2005 silverado 1500 rwd 5.3L. every now and then i go to start it, and it won't turn over. dash and gauge lights come on, but the starter won't engage. usually when this happens, i just let it sit for about 10 minutes and then it will start. the truck is driven regularly, almost daily, and will go for months without this happening, then all of a sudden the problem will crop up again and then happens a few times over the course of a week or two, then it disappears for a while again. anybody else ever have a problem like this and figured it out?

[CamGTP]

An easy thing to do is remove all the battery cables/grounds and clean them all. Find the ones from the battery to the starter, the alternator, the grounds to the body and the chassis. Even the body to chassis ground straps.

[sefiroxx]

Yep, had the problem on my 04 Sierra. It eventually got more frequent. Ran the gauntlet with ignition module, relay, etc. Eventually figured out it was a dead spot on the starter windings.

[cybern8]

thanks - so i assume that meant new starter? did you strip down the starter or how did you know there was a burnt spot?

 

only thing i'm not clear on is if that is the problem, why would it eventually start because the starter isn't getting engaged even slightly (on mine, anyway). i turn the key, and the only thing that happens is the door chime sounds and the dash lights go dark until i release the key... no mechanical noise at all that i can hear other than the turning of the ignition switch cylinder.

[sefiroxx]

After diagnostics, I replaced the solonoid and still had the problem. Pulled the starter, ran resistance test on rotor windings while turning to find some gaps, replaced it and no problems.

Possible problems:
- ignition module
- security system
- neutral safety switch
- relay

Diagnostics:
Working backwards

- check fuses
- check large power line at starter, 12v
- Use a short wire and jump the solenoid from the power line, it should crank
- swap relays, check for constant power at relay and no power at control line (tied to ignition swItch). In start mode, should have power on control line. If not, then nss, security or ignition module.

As for the dead spot rationalization, I gather that the solenoid, when engaging, would extend the starter gear into the flywheel, causing it to rotate a bit on metal to metal contact. Enough hits, and it clears the dead spot. No proof, but a theory. Replaced the starter and everything works.

[cybern8]

wow. you really did crawl through it; very impressive. i'm still skeptical about the burnt spot in my case, because even the slightest contact of metal on metal as you say i should be able to hear, should i not?

 

regardless, thank you for the reply. and i'll roll up my sleeves and go through things to see if i can cure it.

[txab]

I've seen starters that made no noise when you hit the switch  Would whack it with a hammer. Hit the switch and off she goes