I guess my button to disable overdrive on my shift lever doesn't work because I can't disable O/D. Im running 35" tires and on hills I would like to disable O/D so my transmission will stop constantly changing between 4th and od. Is there another way to disable it? Thanks

 

I would say check your fuses first. then pop out the actual switch and test it. if the switch is bad itself , then you can order a new one.
https://www.autozone.com/drivetrain/...h/dodge/dakota

If the switch is good,, you might need a Transmission kickdown solenoid.
It might also be good to check all the connection plugs on your transmission.
what year is your dakota?

 

The O/D off button just completes a circuit to/from the PCM. The PCM then disables O/D, and turns on the light. The wires for the switch are absolutely TINY, so, they may just be broken, or it might be unplugged.

 

I had a similar issue on my 98's O/D button. I found out that if I lifted the back of the snap ring that holds the button in maybe 1/32"~1/16" the button worked fine. Further testing showed that if I pressed harder on a certain side (when the ring was fully seated), it worked reliably (towards the front initially.) So I took the ring off, turned the button around, and replaced the ring. Now I just gotta make sure to press it near the back of the button and it works fine. I'm assuming it just built up some dust/grime under the contacts of the button and pushing the one side helps get past it. Either a new button, or fiddling around for pressure points might help you.

Edit: Also, 4th IS overdrive, assuming by your name you have a 97. You haven't mentioned any specs on the truck you're asking about. Also you can test by using a small jumper wire or paperclip. Pull the button, place ends of wires into holes to bridge the circuit, same effect as pushing the button. Do this in park, engine running. OD Off should light up.

 

Is there an o/d off fuse? Or, what fuses could be doung this? Ive tried taking out the clip and looking at the wires on the switch, nothing so far.

Im assuming my kick down solenoid works fine because on the highway the truck goes in and out of o/d fine.

 

No there is not. The OD off button just shorts a PCM pin to ground, telling the PCM to not activate the overdrive clutch solenoid in the valvebody. Check continuity to ensure the button itself works, as HeyYou said, they are tiny and liable to break inside the shifter arm where they are braided.