Pointers on a no crank problem please

Finished switching out a transmission for a buddy today, he has a 2005 Impala 3.4lL, I used a tranny from a '05 3.8L, just had to change a few brackets. Got it all back together and when go to fire it up, turn the key and nothing...I used a test light and got power on the hot post of the starter and when key is turned to crank position, the control wire gets juice and lights up the test light, but starter don't make a sound. I jumped the hot post to ground and the starter spins but don't engage the flex plate though.

Could there be something that the PCM is doing to not allow the starter to fire? I would think that if that was the case the control line at the starter should not be getting power when key is turned to crank...

Then was thinking something to do with the transmission gear selector switch, but I don't know of a way to verify if that is it or not. It sure seems like it though, for its just like trying to turn the ignition on when its in gear.

I printed off the schematic of the starting system, but must admit I am not too good at reading them and being able to run through it diagnostically..yet..working on it tho! Would anybody have any pointers for me to try, I only have a test light, multimeter and a genysis evo scanner. I'd post the diagram if I could but I can't seem to figure a way, since I am accessing our shop computer from home using remote control software. I could print it out on my printer but can't seem to figure a way to print to a file that I could then transfer over to my pc.

(its running an oxygen sensor code, but doubt that has anything to do with this issue)

I think all the shift selection, as far as the pcm is concerned is done externally as far as starting in gear. I think there is something called shift lock and it is outside the trans. Did you make sure there were no bent pins on the cable that plugs into the trans? sounds more like it is something wrong with the BCM. Most of the devices like motors and solenoids throughout the car will have the voltage at the + of the device, what the PCM does is connects the - (negative) to ground to activate. you don't have adobe acrobat ? if so there should be an adobe "printer" you can print to in your printer folder to create a pdf, also have seen print to a file I am sure, where I suppose if it was in word . also even though the the trans are both the same year and they are both 4T65E's there may be differences inside that their appropriate PCM's have software for.

I use Foxit PDF reader and it allows the print to pdf printer function as well, but all I get is a blank sheet with name of the schematic along the top.

I used the old starter from the donor car and it solved the issue. I guess the solenoid of the original starter was pooched.