Converting an '18 classic 2500 tradesman with the stock 5" screen 4 speed blower fan.
I can't say enough good things about
@Mpgrimm2. I bought a 8.4" radio with AA/dual zone bezel locally on Craigslist for $100, the wiring harness and blower components from mpgrimm2. Turns out the radio was a dud, he talked me though some simple diagnostic ideas via email and over the phone, before I ultimately bought an 8.4 AA unit from him. He was amazing to deal with and instructions for installing the wiring harness were clear and easy to follow.
He let me know of the possible blend door issue with the radio and how to solve it w/ an extra dongle and Alpha OBD. Sure enough, my blend door was acting wonky, for anyone interested I found a work around for it w/o having to use AlphaOBD.
My blend door lever goes all the way down when I press max a/c.
When the a/c is off, and I start at 'hottest' temp, lever only goes about 75% of the way down when I press the soft or hard key long enough for the temp slider on the radio to get all the way down. I have to press the soft or hard key another 8-10 times to get the blend door to go all the way down.
I can't say it will work for you, but worked on my truck