Ok, so here's the story. . .
I always fix cars forwhoever and what not, and this time it was my friends 2002 Blazer. I diagnosed it as a starter and she said shed go and get one. So the next day we meet and she gives me the "new" starter. She went and bought a used one from somewhere in town. So I went ahead and put it in. It started and ran fine.... for about 2 weeks. I went to go check it out and thought it was the used starter. I took it out and bench tested it. The result was bad starter. So I told her to go get a new one. Well she came back with another "new" one. This starter didn't look that good at all. I didn't think to test it, just put it in. Well... This time she cranked it and sure enough it just went click. I said what the hell let's try and jump it.... Click. She tried twice till it made no sound. I pulled the starter out, bench tested, and it shot out "click", but didn't spin. So I told her to stop buying used and go get a new one. While she was gone I was pondering why it eventually made no sound. Well she got back, put in brand new starter, push key forward... No sound. Except a few relays clicking.

Here's where the main diagnosis kicks in. With the key forward twice, the gauges don't move, the radio works, and in cab lights work. If the key is pushed forward to start, there is a really fast clicking under the dash (relay). But, when I pull the key back it continues to click fast and distorts the sound of the door ding and makes the in cab light flash, until the key is removed. I put it back in, and it dings fine, light works, and no relay sound. Push forward, repeating results.

So does this just mean that there is a relay that's gone bad somewhere due to faulty starters? Or is there something else. Btw, I did try swapping the starter relay in the under hood fuse box with no result.

Sorry for the long write up
Thanks

 

Ignoring all the other stuff.. from your key-on action, it would seem like the ignition switch is toast. I say SEEM like. Also ind of low battery in some case or bad cable connections.

Beyond that I find it difficult to believe that all those starters were bad. Bench testing starters is tricky.

Think you need to go to the basics.. battery charge > Terminal connections, POS and Gnd!> Hidden fail inside Terminal/cable connections.

 

Dead battery. Sounds like the battery has enough voltage - and that will make the test look good - but it doesn't have the amperage to crank the starter over under load. Should have at least 10-11v while cranking. Anything less isn't going to cut it.

 

If this is any help, I tried jumping it with the exact same results. In my experience, it sounds like a battery problem to me too. I'll trace the actual starter cables later today to see if they have a good connection.