My ram 1500 wont shift into first gear and will not shift into overdrive. it sends a error code of P0750

that is the generic OBD2 code3 for transmission errors
shifting solenoid A fails (or slips)
evidence and causes.

• Check engine light glows. and P0750 is set.
• Limp mode (slow speeds only)
• Delayed, harsh or erratic shifts
• Harsh 1-2 shift
• Slipping through the gears
• Slipping on the 1-2 shift
• Engine stalling
• Getting 'stuck' in a gear
• Vehicle won't move when in gear
• Decreased fuel economy
• Transmission overheats

there are more tests to do, but you have no tools to do that.

When did you last replace trans filter and fluid? Dirt may be causing shift valve to stick.

CHECK FOR POWER TO TCC. WHEN ENGAGED .IF YOU HAVE NO POWER THE OD SWITCH IS MOST LIKELY BAD

You need to replace the internal solenoids. Not a hard job. Drop the pan, remove the PWM solenoid, and shift solenoids. PWM is causing this issue. New solenoids will cure it. Kit on eBay is $255. https://www.youtube.com/watch?v=yOABDeJQrAE&vl=en https://www.ebay.com/itm/Ram-45RFE-545RFE-68RFE-Solenoid-Assembly-2004-Up-Dodge-Chrysler-Jeep-Mopar/351629865164?fits=Year%3A2005%7CMake%3ADodge%7CModel%3ARam+1500&epid=1853258599&hash=item51dec5f0cc:g:BI4AAOSwjDZYZrmf&vxp=mtr

TIme to have the solenoid replaced or ****** rebuilt if you feel up to it. Solenoid is the usually the cause.

The kickdown on transmissoin controls the up shift and or down shift by the throttle pressure it is out of adjustment.

0753 is shift solenoid A, electrical problem.as for the other codes they should start with a zero not a one. if they started with a 0757 that means shift solenoid B,stuck in on position. 0762 means shift solenoid C,stuck in on position. 0765 means shift solenoid D,malfunction

the p0750 is a shift solenoid A malfunton,whice in turn will set the p0700 code,if you change the shift solenoid that should get rid of both codes.