Eaton Auto Shift will not go into Gear

Yes, mechanic had swapped the input and output sensor wires, thus showing no input shaft speed. Also replaced the sensor, tested fine, but looked rough when we pulled it. The day I posted something seemed off, and was not going to go throwing parts at it (ecm, clutches etc.) I tested the old X-Y when the truck came in ( removed it and watched it work, or in this case not work). Harness was original, and wanted it replaced along with speed sensor.

I called a local shop with a pro-link to comedown and hook up because I wanted to read the data streams. I had a N, just was not wanting to engage. Once hooked up, and clutch was released, we had 0 rpm at input shaft and 1300 at output shaft. switched the plug and truck ran great. 10 minute fix. Our mechanic felt bad, but crap happens. This is why I do not throw parts at a fix.

Everyone who said to check the connections was dead on before you replace anything. These things need good grounds and connections. Also, if you are there, spend the 35.00 for a input shaft speed sensor. These things can test good (2k ohms across the sensor connector) but still be bad. They have a magnet in them, and if they go bad or weak, cause havoc. This truck, shifts smoother than it ever has, and that was due to the sensor wear.

I had about 1500.00 in total cost for parts and labor. Being a small fleet, way cheaper for me to fix in house than a shop. First fix for us on a AMT, will buy the software next few weeks to plug in for them. Every shop I called started at around 3500.00 to start if just X-Y. These transmissions are very easy to work on, Eaton support is good, and was a great learning experience. If the mechanic had not screwed up, with the harness and X-Y and new sensor was a 3 hour fix.

Thanks again to everyone who replied, great group of people on these forums.