I have a 99 chevy blazer 4x4 with a 4.3 Vortec motor. I bought the blazer at a good price, the guy thought the transmission was going bad and all it was the shift solenoid bad. After a hour worth of work i had it running and shifting fine drove it for about 6 months maybe one day a week more when hunting season is in. then one day i went out to go hunting and the truck would not crank just kept turning over and burping back up through the throttle body. after killing the battery three times and charging it back up it eventually would crank, as long as i started driving it everyday it would crank just fine but if i let it sit for a couple of days it would do the same thing again and not crank. which brings me to my latest problem, i finally got it to crank the other day but when i went to back it out of the drive it went into reverse but wouldnt move so i put it into all the other gears and still will not move. I am curious if me disconnecting the battery, moving and disconnecting wires, an disconnecting the computer on the first problem caused the problem with the transmission. I was thinking i might have a bad PCM now.

 

If you put it in gear with the engine running it should try to move.
Turn the engine off, put on the parking brake and get under it. Check the shifter linkage for smooth operation.
Also check the tranny fluid... is there any?... is it burnt and dark in color?

 

also try disconnecting one of the tranny lines going into the rad..if it spits fluid the tranny is moving fluid...if not then you have a tranny issue.

 

The fluid is full and still red as when i put it in. i will check to see if it spits fluid out.

 

I added a quart of tranny fluid and it started moving slowly. I have it parked on a small incline and it had been there for 3 weeks. Once I got it back on level ground it started moving and shifting good. Drove it around the block and the tranny is back working good. I like the blazer but it might not be worth keeping since I dont drive it everyday. It seems to have issues when its not being drove on a consistent basis.