PLEASE HELP!!

I have a 94 automatic accord ex that won't shift into overdrive. The original transmission stoped shifting into overdrive so i changed it. With the new 30,000 mile transmission still same problem; NO Overdrive. Changed it again; same problem! 3 swaps later still NO Overdrive. I have checked the silenoids, the temperature sensors, the ecu, tcu, trottle body cable, torque converter, the shifter, I even changed the Engine harnest. I have checked or changed everything. I am at my wits ends with this car! There has got to be someone out there that can help. Seriously i have checked or changed everything that could possibly be it.

 

I can't recall off the top of my head, but isn't the AT harness divorced from the engine harness? If so you may want to look at that harness separately. Are you sure its 4th gear and not the torque converter lockup?

Did you already trouble shoot using this link?
http://techauto.awardspace.com/transmission.html

It's highly unlikely that 4th in both transmissions is bad, I would test the wire harness between the TCU and transmission. It simply could be a corroded or broken pin in the connectors for the shift solenoids.

Did you try to pull any codes and see if there was one set?

 

Thanks guys for the help. Know now that i think about it the car has a leak, on the passanger side right above the the area where the TCU is located. The I wonder if this caused coerrotion or caused wiring to go bad in that area. The car once had all the windows broken out. Windshield, door windows...etc They were replace but perhaps a bad job caused a leak in through the passanger side so now everytime it rains, water gets in right above the TCU area.
PS. how do i get codes or troubleshoot to check the solenoids?