Chevrolet Trailblazer won't crank to start

[depotdave]

After rebuild, engine starts and runs like a top. Problem is, it didn't want to stop running. I could turn the switch to "OFF" and even remove the key and engine was still running. Got it to stop by putting key back into ignition, putting the transmission into R and turning the key to OFF. But, check engine lite stayed illuminated. Next morning, no crank and no start. A jump start got it running again. Engine started to operate as normal, and check engine light went out, but the other morning, again, no start. But again, a jump start worked. Since then, at work or at home for the evening, I remove the ground cable from the battery and it will start when reconnected. So, is it the ignition switch? Any help will be appreciated. Thanks.

[carriedi]

yes, it sounds like you have a problem where the ignition switch is not turning all the way off. you're going to have to find out if the switch is bad or the lock and tumbler is damaged.

does the key feel normal when you turn it on and off? you know, like do you feel the click for each normal detent position?

what is the year, make and model of your vehicle?

[depotdave]

This is the same 2005 trailblazer as the No Crank problem truck. I will this evening check on the detents of the switch and of the tumblers and report. thanks for your thoughts, already.

[devten71]

My 2003 trailblazer won't crank,I took the alternator out and had it tested as well as the battery and finally the starter and they all are fine....then I pulled the starter relay and checked the slots and I have power to the first slot and no power in the second slot and no ground on the lower first slot so I'm asking we're do I look??

[carriedi]

I am not sure about what you are talking about on the slots concerning the first one, second one.... there are four pins on your relay. Does your relay have the electrical diagram on one of the sides of it? If it does not look to see if there are other relays that show the diagram that shows what the pins go to. pin 85 and 86 are for the electromagnet to pull the contact down. pin 30 should be battery power. pin 87 should go to your starter. the pins work with the diagonal pin. That's why it doesn't make any difference which way you out the relay in. The pins should be numbered on the bottom of the relay next to the pin.

[Underdog]

Its your ignition switch . controls all that

[carriedi]

the ignition switch supplies power but the PCM turns on the starter

[kinsy2323]

My trailblazer started but sounds rough and acts like it is having problems staying on.
I pressed the accelerator and it won't Rev up. I just turned it off.
What kind of problems could this be? I was thinking fuel pump, regulator or injectors.
Any ideas???

[carriedi]

that could be any of those things or none of those things. you should have the vehicle scanned to find out what is going on. Idle control, mismatch air/fuel ratio, fuel trims, 02 sensor working normally, cat plugged up, throttle problem, misfire from either fuel or spark. without scanning to see what the computer is reacting to, everything is just a wild guess. Just replacing parts could get expensive.