I have a 97 blazer and over the summer the tranny went out and after slowly working on it the last 6 months it's finally all back together. I pulled the tranny out a 98 and slapped it in mine using the torque converter from the 98. I got it back on the road and drove it for about 40 miles. Went to take it to get an alignment today and made it down the road. When I stopped at a stop sign it wouldn't take off. It is in limp mode. I got it home and pulled the following codes.

P0740P0758P0785P1860P0155 pending P0713 pending P0740 pending P0753 pending P0758 pending P0785 pending P1860 pending

After I cleared them all I fired it up and after about 10 seconds the SES light kicks back on and I get the following codes

P0740P1860P0785P0740 pendingP0785 pendingP1860 pending

I checked the fuse with a test light with engine running (volt meter is at work) and had power on both sides of the fuse. I am at a loss and I personally think it's the ignition switch but it fires right up although runs a little choppy.