I have a Ford 2001 ranger 4x4 original owner. My car appears to be shifting into 4 low or tries to while driving. This has happened 3 times over 3 months. The 4 low light on the dash was lit and the switch was still set to 2 wheel drive. I car grinds while this is going on it appears to be coming from the transmission. The speedometer arm was flipping from 0 to 60 mph. I pulled the car off to the side of the road and attempted to take off in 1st gear and the car jerked violently front to back. I turned the car off and the 4 low light was off put the car into 1st gear and drove normally.
I am going to guess a speed sensor or the connection to it.
In any case my replay should bring this message back up on top and maybe transman will see it and reply.I think you have a short in the dash wiring harness somewhere and what seals the deal for me is the flipping speedometer. That’s something you should have checked out ASAP, and at the very least you should try to find a way to make sure that it can’t shift the transfer case by itself. Going in to 4 low at any amount of speed is really, really bad for the transfer case (and it’s not too good for the drivetrain overall…)
I have the car at trany shop at the moment. They have done a full electrical system check and all is okay. They believe the motor for the transfer case has an electrical issue. They said that these trucks have issues with them. That seems odd to me, but at this point it is the only thing that anyone can point to. The Ford Dealer looked at this issue 3 times with nothing to go on. Given that this issue only happens once a month I will have to wait and see if that fixes it. Thanks for you input.