Sorry. I missed that one but I don't think it is related to the overdrive issue.
Here is the test for it not working at all. Let me know what you find with this but due to the fact that you already replaced the speed sensor, and assuming your brake lights work, and horn works, then it may just be out of adjustment.
I attached the test and the adjustment procedure. The adjustment procedure is pretty lite so I looked for more information and couldn't find it. If you need more, let me know and I will try to dig deeper. Thanks
Images (Click to make bigger)
Tuesday, May 4th, 2021 AT 10:08 AM