I have a '97 Expy that I tow a travel trailer with frequently. I always hit the botton to take out of O.D. The last time I did this,
the light came on and after a little while, began to flash and eventually went out. Now, I can't get the button to work at all.
No light or anything. O.D. seems to be working fine, but I just can't kick it off when I would like. Do the switch's go bad, or could there be other problems? Thanks in advance for any advice!!

 

The same thing happened to my 97, and after a little searching, I found that the wire inside the shift arm burns out. First, check your fluid levels, and inspect to see if the fluid smells burnt, etc. This will rule out a mechanical problem. If everything looks OK, you have to pull off the steering column cover, and the lower dash cover. Inspect the base of the shift arm, and you will see a small wire coming out of it, running down behind the dash. If you follow it, it leads to a plug-in connector. Inspect this wire, and you will see it has burnt out somewhere along the line. This is caused by years of bending back and forth, and it shorts out. Verify the wire is shorted by testing for continuity.

Now, to make a new one, it is a little tricky. Use a small pick to pop off the end of the shift arm. It is a small ring that holds the
OD switch. The OD switch pulls right out. Now, remove the shift arm by taking out the small pin at its hinge point. Remove the arm, and unplug the OD wire below the dash. You will need a piece of telephone or intercom wire (small 22ga. 3-conductor). Pull out the OD switch socket. Check the color of the wires at the connector and the OD socket, write them down. Now cut a piece of new wire to length, and solder it onto the OD socket first. Remeber your colors ! Now the tricky part, thread the new wire through the shift arm, and solder the connector on the other end. Check your solder joints with a continuity tester. Reassemble the whole lot, and everthing should work. I know this sounds complex, but it worked for me. I am not sure if you can buy a replacement wire from the dealer, I think you have to buy the whole arm assembly. Anyway, good luck !!