2003 Chevy Blazer Won't Start

If you are experiencing that problem you mighy have a lack of fuel to the engine. In this case the engine will crank over and sound as if it wants to start. A quick test is to turn off all accessories, turn the key to on and listen for a low volume humming noise. This noise is the fuel pump. If there is no noise it is likely the engine is not getting fuel. A blown fuse, faulty relay, or bad fuel pump may be the cause.

Yeah, the fuel pump is running and I've had it tested twice by dealer mechanic - they can't find anything and don't have a clue to why it won't crank. I've been slowy replacing cheapest parts with a hope to finding the culprit. I think it has to be electrical, but don't know where else to look. Every time the dealer puts it to their computer to diagnose it, they come back with nothing.

I have had a service light for an O2 sensor - but they said that wouldn't stop it from cranking.

Maybe I need to fix that and see if its masking something else.

Thanks.