Wiring Help Needed

I HAVE A 94 HUMMER WAGON THAT DOES NOT CHANGE OUT OF FIRST GEAR. I KNOW IT IS AN ELECTRICAL PROBLEM RELATED WITH THE TRANSMISSION CONTROL MODULE. DOES ANYONE KNOW WHERE I CNA GET WIRING DIAGRAMS ON THIS RELATED ISSUE OR HAVE ANY IDEAS WHAT THE PROBLEM MIGHT BE. THE SPEEDO DOES NOT WORK EITHER. THANKS.....JAN.

You should have a 1/2 shift solenoid that either isn't getting signal up to it, doesn't work or the spool valve doesn't work. That's just for first gear. If all of the other gears work fine then the pressure control valve works fine.
PM me.:2cents:

If you have the 4L80-E transmission and if you have a transmission problem. You have a stuck checkball at the 1-2 shifting solenoid or the shifting valve is sticking and not returning.
I will describe the operation to you.
The computer controls the first gear in this manner.
By controlling the ground switch in the computer. when the puter decides enough is enough and lets go to second then it opens that switch and denying power to the 1-2 shifting solenoid. When that happens the pressure bleeds off and the valve relaxes and into second gear you go.

Provided the ECU is reading everything correctly like engine load and rpm.

which type of help you needed..??
==========
albert
used caravans (http://www.caravanmarket.com.au)

Do you want a wiring diagram to fix the problem yourself or some suggestion on how to fix it. Its not clear

Most likely it is not the wiring. It could be soleniod related.

Disconnect the passthough connector at the transmission. At the transmission side there are pins E and A. test those for resistance. I believe the resistance should fall into 14 ohms. Definitely not over 20 ohms.

You can check for continuity as well.

If all seems to check out well then drop the pan.
Get two nine volt batteries. Soldier them in series with two leads. Test the two leads right on the solenoid. You should hear a clicking sound.

You can also conduct the very same test at the passthrough connector. If you hear the clicking sound then you are good.

Check all grounds with a multimeter. .1 ohms from terminal to ground. Everywhere you go to check a ground. If it is higher then remove that ground and clean it. Recheck. Battery ground. Block. Battery to chassis. I mean everywhere.
If in the event that everything is checking out then remove the soleniod. There is a pressure checking procedure that is not done so much nowadays. Replace it. A 3/8s star socket and a ratchet are the tools.
You might have a hanging valve that doesn't want to move after actuation of the 1-2 solenoid. That will be verified after replacement of the solenoid.