Where is the starter in a 1999 4-door Chevy Blazer and how do I test to find out if it needs to be replaced?

but is the battery really good?? put the lights on and hit the starter,,,did the head lights stay bright or dim out...poor mans load test..

Have the battery tested at the parts store. Just because it's charged doesn't mean it's good. Or maybe have someone jump you off. Other than that you need a starter. Once off you can take it and have it tested too.

I went to look at a 97 s10 blazer 2 door 4wd that I was interested in buying. The guy said he always had to jump it from another car to start...he replaced the starter, plugs & wires and was intending replacing the alternator next. He put it up for sale at that point. I came prepared with a spare alternator and two side post batteries to drive it home after intended purchase. Replacing the battery did not advance any positive additional action from the vehicle, granted a fully functional dash, lights and just a fast, full battery powered clicking...... It was late and cold so I kept my money tucked away and bit my Chevy sweet tooth and camped out for the night in town looking at any other vehicles for sale online in the area and price range. The next afternoon deciding that the battery I brought should've gotten me outta there for a few miles in my new Chevy so swapping alternators would be pointless. I was at the highway on-ramp about to say nope to purchasing this one and go home. I forced thought, lets go to the truck real quick and catch a daylight glimpse, cuz I know I wouldn't rest easy on all the "I could've" or "what if's" at least yet. Time crunched on us and the seller I made an offer comfortable enough to get the title so he can go to work and I can drive away in it if successful or leave it as another dud to come back and haul away later and not broke. I hooked up a charger to my battery a few feet away while I went on to removing the one in it...noticed a familiar scenario I had been in before and treading lightly went on with it...long story for such a short fix I apologize... I disconnected the ugly positive terminal side post bolt on to the wire type clamp and stripped back fresh wire on all wires involved (positive side, 3x fyi). Scraped all metal to metal pieces involved and put it all back on securely. The main big wire clamped in the center groove and an eyelit electrical connector on each of the other wires to be secured by the bolts on the clamp when tightened fully. Grabbed my battery and threw it in, locked in the negative side, tightened the positive, good 'ok 8mm back in my pocket, key in ignition and the truck fired up and idled perfectly :) !! I drove it immediately the 3 hrs home.....alternator, starter, everything was original and functioning. The following days about three later it wouldn't start at the cell phone store...my heart dropped. I literally shook my head put on my gloves and jacket and popped the hood to do the only thing I knew I could, at least here and now. I had to tighten up the bolts holding the wires on the side post terminal clamp and reconnect it to the battery. It started again :) whew...to the parts store I go and got a new gold side post terminal clamp and been driving it since....so many miles in the month I've had it that I find myself to this site troubleshooting a recent and well earned fuel issue. Replaced the pump with a donor used one that had to be himmed and hawed to be the one...swapping the wiring within the pump assembly, filing down a tab to be flush on top and swapping the rubber gasket seal under the top of the pump also....jerry rigged, but diagram to operational needs, precise. Tank, harnesses and fuel lines re connected and bolted in...the truck fires up perfectly..idles while thawing for half hour just fine...driving my friend/ Chevy surgeon home, two miles down the road, dies in motion. Starts, sputters and dies. Indefinitely. Pushed it into a parking lot, then checked fuel pressure. It's at high 40's and before the pump swap it was at 10psi. So pumps good, I hear it priming loud and clear...again, pumps good......so.....! A week later do What I should've done the night I swapped pumps...replace fuel filter under driver side by frame. Nasty, dirty, black leaks out of the old one. Clear fuel dripping from rear line coming from tank and pump...install new filter. NO START, NO FIRE, and worse yet....NO PRIME, NO PRESSURE. Here I am. For the moment at this position. Recent learnings that the 'ECM BATT' fuse is my pump so that is my next to check when I can get back to my truck...Im pretty sure I identified every fuse as good and made it be just for principal on site after the filter fail...but that's again, my only go to other than diving in again to check for 12v power into the pump..yes I heard the relay working but will get an assure voltage reading also when on site again. Direct knowledge and troubleshooting tips are definitely accepted and please, by all means aside from the obvious (dropping the Tank, putting in an unaffordable new fuel pump and re working the system piece and part renewing as I go..all the way to the evaporation of the fuel molecules). THANK YOU VERY MUCH, I LOVE THIS FORUM !!

You can’t tell the difference between a 2 door and a 4 door? It would be a waist of time to explain where starter is....

A 4 door has the most doors , maybe this will help u tell a 2 and 4 door apart.