Strange no start issue

[04hoedown]

I've tried searching for a solution, but have had no luck. This is a very intermittent problem. One day it will do it, then it won't do it again for two weeks. I've had it happen twice this week, so now I'm wondering if it's getting worse or just luck of the draw.

Anyway, when I jump in the truck and try to crank it, it doesn't crank. The lights all dim down like its the battery even though both the battery and alt seem fine. Battery is less than six months old. I can sit there and turn it off and to start again a thousand times and it will act the same way. However, if I leave the key in the on position for 10-15 seconds and then turn it, she will fire right up like nothing was ever the matter.

I'm not sure if there is a short or a bad connection or what. It's just so weird and spontaneous I can't really nail down the problem. Like if I was to take it to a shop, they could have it for a week and it wouldn't do it to them once or even if it did, it would correct itself before they could even begin trying to diagnosis it.

Hopefully others have had the same issue or at least have heard of this before.

 

[zieglerj-pdm-specialist]

Does your vehicle have an autostart installed on your Tahoe. This sounds exactly like what happens on my 1997 Bonneville SSE. I get it and it truns on all of the accessories but when I try to turn it over I have nothing. When I have someone try to jump me it doesnt crank but sometimes it cranks with no problems what so ever. This happens when the car hates me I think. Its is very intermittent and I turn the auto start on and off a couple times and then it seems to work once and a while when I do that. I have no clue what makes this happen. I hope you get an answer because I will be watching this thread to see if there is anything that may remedy this nuisance.