Just bought this 2002 "xtremely sad" Blazer shifts out of 2nd but doesn't hit 3rd
 

Just bought. Check engine light is on. 250,xxx odometer.Shifts out of 2nd but wont shift into 3rd. Just goes into neutral and the RPMs go high. Does it in 2hi and 4hi (assuming the same for 4lo). Pulled TCM fuse (it's good). Started it, let it sit for an hr before replacing fuse. No dice....same symptoms. Sometimes I hear what's sounds kinda like a relay clicking on and off and sounds like it's coming from under the center console? Engine seems to miss and kinda fall on its face. Might be a bad plug wire arching off the block (haven't determined this yet).

Sometimes I think I can get get it to slip into 3rd shifting from 2nd into D manually but not certain (rpms stay at around 4000 at 50mph.)
Tranny was reading bone dry at operating temp, put in a couple quarts......same results.

Btw it's a v-6 4wd. And I'm probably the farthest thing from mechanically inclined (zero patience and always without the right tools). Changed a timing belt on a Kia Sedona once....blew it up and left it for dead on the shoulder the next day. Might call me somewhat gun-shy in regards to auto repairs.

Already a lil worried about what ya'll'z answers will be..(hyperventilates slightly.....lights a camel)

Welcome to the forum.

My first reaction to your list of symptoms about the shifting is that your 3/4 clutch pack might be bad and slipping. Look for discussions of this failure in the transmission (I'm assuming it is an automatic) here and elsewhere. I had mine wear out and start slipping, just as if it was going into neutral instead of 3rd when you'd expect it to upshift from 2nd. I did this to myself as I did many years of towing with my Blazer pulling a 2,200 boat and trailer while using over-drive (4th gear). Lesson learned the hard way.

I have the same symptoms but I know the transmission is hurt. I had line pop off on the highway and the fluid leaked out. What you can do is make sure the level is right i.e. shift the gear and recheck the level.

That is a long shot but it appears the trans is need of a new 3-4 clutch pack and the seal that keeps the fluid pressure there at a minimum.

I am having my trans rebuilt with the upgrades to the valve body, corvette servo and a cooler so I can get another 200k plus out of it.

Seems now is the time for transmission troubles. A week ago, I was on the parkway, doing about 60, then noticed I was revving high but not really going. Slowed down to notice I can get to about 40 mph. Seems like it won't shift into overdrive. I pulled over, shut it off, started back up went away. Have driven back to PA and back to Jersey since with no issues. Yesterday, on the parkway again, same thing. Driving, then high revs with no power. Pulled over, shut it off, started it again and it went away. Aborted my trip and headed back home, it did it again. Stopped, shut it off, continued on my way.
Any idea what this could be? It's got 85k miles on it and about 4 years ago it had almost $900.00 worth of work done on the transmission. Fluid level is fine, although the guy at the shop said it should be more of a bright red. He suggested dropping the pan and seeing if there are any metal flakes in it. So that's where I'm at, waiting to see this outcome. Anything else that may be a simple fix? I just spent a ton of money a month ago, only to find out it was something as silly as a busted spark plug wire. I really don't have the money for a new OR rebuilt transmission.

Lefet

I can tell you that the news from the pan being dropped likely won't be good. Had a 700R4 in an '88 blazer that started doing that and there was significant metal in the pan. If I were to hazard a guess I would suspect a torque converter or trans pump but I'm just spit balling. Let us know how this turns out for you.

If it was run low on fluid it will be the 3-4 clutch pack burnt as stated above. Plus many other worn parts with that mileage. I would venture a guess that that transmission has been out once maybe twice. Good luck.

What would be the best way to find out exactly what the problem is?