2003 Blazer used to crank but not start, now won't crank at all
 

I wasn't sure if I should post this in General Tech or here, because I'm not sure if it's an engine problem or an anti-theft problem.

My '03 Blazer 4WD has started giving me an intermittent starting problem. Over the last few weeks, all of the electronics would come on when I'd turn the key to ON, but the engine would just crank and crank and not start. Usually it would start up again after a while and run fine for several days, and then the problem would come back again. I've been working under the impression that maybe it was an anti-theft issue, but I've started to wonder about that since I've never seen the "SECURITY" light come on when it won't fire. I was about to buy the NewRockies.com security bypass module, but something in my gut kept telling me to hold off...

Today I went to start it, and all the electronics came on like normal. Battery voltage was reading around 12-ish volts (it's a new battery, installed about 3 months ago with a 2013 date code on it). But when I tried to crank it... nothing. No turning over, not even a solenoid click. Just completely dead. But the radio comes on, the headlights come on, the windows work, etc.

Still no "SECURITY" light. The SES light is on, but has been for a while (last code check was for gas evap - the O-ring on the gas cap is old and cracked).

Are these problems related? I used to think that it was an anti-theft issue, but the lack of traditional warnings has me confused.

Anyone have any suggestions that I can try at home to diagnose, rather than just throwing money at it at a dealership?

I've gone out and tried again, still no luck. If I turn the key to ON without trying to start it, all the dash lights come on for a moment, I can hear the fuel pump running, and then all the dash lights go off like normal, including the SECURITY light. Except that when I try to start it, it won't crank at all. It just sits there doing nothing with the engine.

I always thought that if the security system was going bad, the truck would still crank but not light.

Any ideas anyone?

for the no crank part it could be the selonoid on the starter - i've had them fry from extended cranking - have somebody turn the switch to start and check for power with a test light at the small wire on the selonoid - if there is power there i'd drop the starter - most part stores will be able to test it for you -

Have you checked the crank fuse?

Never did close this thread out. I apologize.

Turned out that the ignition coil had gone bad and was arcing outside of the casing. Replacing the coil restored normal operation.

Thanks.