My son bought a 2003 Blazer two days ago. When he picked it up at the guy's house it was running, so he didn't get to see it start there. It had been sitting for about two months without being driven, but we were told it "started right up." He drive it 15 miles home and parked it overnight. When he tried to start it to go to school he had a no start. The solenoid clicked once and the starter didn't even try to engage. The fuel pump kicked on, the dash voltage gage rose up to ~12 volts, the door bell and all the lights inside came on as normal. This is all second hand from his mouth as I was working when it happened. He said he jumped it with my wife's Suburban and it started right up and he drove it to school. Yesterday afternoon he came out after school and it wouldn't start. This time I went up and looked at it.

Same deal, clicked once and nothing more. Voltage across the battery terminals with a DMM was 12.5 V, the lights and door bell were acting normally. I went ahead and dropped the starter in the parking lot, grounded the starter case to the frame with a jumper cable and had my son hit the ignition. The starter spun right up and ran just fine. Now, the starter was hanging gear down by the wires with me supporting it. I cleaned off the mounting points on the starter and the block, and bolted it back on. The truck started right up three times in a row. He drove it home.

This morning he tried to start it again and it did the same thing. One click and nothing else. I'm seriously at a loss. It seems like a voltage drop somewhere maybe. It doesn't seem like the starter really, but I guess it could be. I've owned a 95 S-10 and a 99 2nd Gen Blazer that both had starters fail and they didn't fail all at once, but rather intermittently failed.

Any ideas where to start are appreciated. I think I'm going to try un bolting everything and cleaning terminals and rebolting to see if there is corrosion causing a voltage drop. Anything else that is obvious I'm missing?

 

Try wacking the starter....could just be the starter solenoid is getting stuck. Perhaps clean the starter terminals and lugs and try again. Also maybe take the postive cable off the starter, put DMM across it and then move the cable around to see if voltage drops out due to a break in the cable.

Just some thoughts.

Good luck.

 

You've somewhat implied you have, or will do this, but I'll say it anyway: check/clean the terminals attached to the battery. Our 2001 is notorious for caked material preventing starting. I finally changed the + terminal a few months ago and have not had a problem since.

 

you could always take the starter to the parts store and have them test it for a dead spot.
Also check connections as stated by joey @ battery and starter

 

I'd put money on a bad battery

 

check the distributor cap and rotor...maybe camshaft sensor....mine was curroded.